diff --git a/rskj-core/src/test/java/co/rsk/vm/opcode/MCopyDslTest.java b/rskj-core/src/test/java/co/rsk/vm/opcode/MCopyDslTest.java
index 5c2b5106d20..8b0b4107f69 100644
--- a/rskj-core/src/test/java/co/rsk/vm/opcode/MCopyDslTest.java
+++ b/rskj-core/src/test/java/co/rsk/vm/opcode/MCopyDslTest.java
@@ -17,6 +17,8 @@
 
 public class MCopyDslTest {
 
+    // Activation Config Tests
+
     @Test
     void testMCOPY_whenNotActivated_behavesAsExpected() throws FileNotFoundException, DslProcessorException {
 
@@ -74,6 +76,8 @@ void testMCOPY_whenNotActivated_behavesAsExpected() throws FileNotFoundException
 
     }
 
+    // Basic Usage Cases Tests
+
     @Test
     void testMCOPY_testCase1_behavesAsExpected() throws FileNotFoundException, DslProcessorException {
 
@@ -128,4 +132,166 @@ void testMCOPY_testCase1_behavesAsExpected() throws FileNotFoundException, DslPr
 
     }
 
+    @Test
+    void testMCOPY_testCase2_behavesAsExpected() throws FileNotFoundException, DslProcessorException {
+
+        DslParser parser = DslParser.fromResource("dsl/opcode/mcopy/testCopying32BytesFromOffset0toOffset0.txt");
+        World world = new World();
+        WorldDslProcessor processor = new WorldDslProcessor(world);
+        processor.processCommands(parser);
+
+        // Assertions
+
+        // There's one block (b01) containing only 1 transaction
+        Block block1 = world.getBlockByName("b01");
+        Assertions.assertNotNull(block1);
+        Assertions.assertEquals(1, block1.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopy
+        Transaction txTestMCopy = world.getTransactionByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopy);
+
+        // Transaction txTestMCopy has a transaction receipt
+        TransactionReceipt txTestMCopyReceipt = world.getTransactionReceiptByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopyReceipt);
+
+        // Transaction txTestMCopy has been processed correctly
+        byte[] creationStatus = txTestMCopyReceipt.getStatus();
+        Assertions.assertNotNull(creationStatus);
+        Assertions.assertEquals(1, creationStatus.length);
+        Assertions.assertEquals(1, creationStatus[0]);
+
+        // There's one block (b02) containing only 1 transaction
+        Block block2 = world.getBlockByName("b02");
+        Assertions.assertNotNull(block2);
+        Assertions.assertEquals(1, block2.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopyOKCall
+        Transaction txTestMCopyOKCall = world.getTransactionByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCall);
+
+        // Transaction txTestMCopyOKCall has a transaction receipt
+        TransactionReceipt txTestMCopyOKCallReceipt = world.getTransactionReceiptByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCallReceipt);
+
+        // Transaction txTestMCopyOKCall has been processed correctly
+        byte[] txTestMCopyOKCallCreationStatus = txTestMCopyOKCallReceipt.getStatus();
+        Assertions.assertNotNull(txTestMCopyOKCallCreationStatus);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus.length);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus[0]);
+
+        // Check events
+        Assertions.assertEquals(1, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "OK", null));
+        Assertions.assertEquals(0, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "ERROR", null));
+
+    }
+
+    @Test
+    void testMCOPY_testCase3_behavesAsExpected() throws FileNotFoundException, DslProcessorException {
+
+        DslParser parser = DslParser.fromResource("dsl/opcode/mcopy/testCopying8BytesFromOffset1toOffset0.txt");
+        World world = new World();
+        WorldDslProcessor processor = new WorldDslProcessor(world);
+        processor.processCommands(parser);
+
+        // Assertions
+
+        // There's one block (b01) containing only 1 transaction
+        Block block1 = world.getBlockByName("b01");
+        Assertions.assertNotNull(block1);
+        Assertions.assertEquals(1, block1.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopy
+        Transaction txTestMCopy = world.getTransactionByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopy);
+
+        // Transaction txTestMCopy has a transaction receipt
+        TransactionReceipt txTestMCopyReceipt = world.getTransactionReceiptByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopyReceipt);
+
+        // Transaction txTestMCopy has been processed correctly
+        byte[] creationStatus = txTestMCopyReceipt.getStatus();
+        Assertions.assertNotNull(creationStatus);
+        Assertions.assertEquals(1, creationStatus.length);
+        Assertions.assertEquals(1, creationStatus[0]);
+
+        // There's one block (b02) containing only 1 transaction
+        Block block2 = world.getBlockByName("b02");
+        Assertions.assertNotNull(block2);
+        Assertions.assertEquals(1, block2.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopyOKCall
+        Transaction txTestMCopyOKCall = world.getTransactionByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCall);
+
+        // Transaction txTestMCopyOKCall has a transaction receipt
+        TransactionReceipt txTestMCopyOKCallReceipt = world.getTransactionReceiptByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCallReceipt);
+
+        // Transaction txTestMCopyOKCall has been processed correctly
+        byte[] txTestMCopyOKCallCreationStatus = txTestMCopyOKCallReceipt.getStatus();
+        Assertions.assertNotNull(txTestMCopyOKCallCreationStatus);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus.length);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus[0]);
+
+        // Check events
+        Assertions.assertEquals(1, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "OK", null));
+        Assertions.assertEquals(0, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "ERROR", null));
+
+    }
+
+    @Test
+    void testMCOPY_testCase4_behavesAsExpected() throws FileNotFoundException, DslProcessorException {
+
+        DslParser parser = DslParser.fromResource("dsl/opcode/mcopy/testCopying8BytesFromOffset0toOffset1.txt");
+        World world = new World();
+        WorldDslProcessor processor = new WorldDslProcessor(world);
+        processor.processCommands(parser);
+
+        // Assertions
+
+        // There's one block (b01) containing only 1 transaction
+        Block block1 = world.getBlockByName("b01");
+        Assertions.assertNotNull(block1);
+        Assertions.assertEquals(1, block1.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopy
+        Transaction txTestMCopy = world.getTransactionByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopy);
+
+        // Transaction txTestMCopy has a transaction receipt
+        TransactionReceipt txTestMCopyReceipt = world.getTransactionReceiptByName("txTestMCopy");
+        Assertions.assertNotNull(txTestMCopyReceipt);
+
+        // Transaction txTestMCopy has been processed correctly
+        byte[] creationStatus = txTestMCopyReceipt.getStatus();
+        Assertions.assertNotNull(creationStatus);
+        Assertions.assertEquals(1, creationStatus.length);
+        Assertions.assertEquals(1, creationStatus[0]);
+
+        // There's one block (b02) containing only 1 transaction
+        Block block2 = world.getBlockByName("b02");
+        Assertions.assertNotNull(block2);
+        Assertions.assertEquals(1, block2.getTransactionsList().size());
+
+        // There's a transaction called txTestMCopyOKCall
+        Transaction txTestMCopyOKCall = world.getTransactionByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCall);
+
+        // Transaction txTestMCopyOKCall has a transaction receipt
+        TransactionReceipt txTestMCopyOKCallReceipt = world.getTransactionReceiptByName("txTestMCopyOKCall");
+        Assertions.assertNotNull(txTestMCopyOKCallReceipt);
+
+        // Transaction txTestMCopyOKCall has been processed correctly
+        byte[] txTestMCopyOKCallCreationStatus = txTestMCopyOKCallReceipt.getStatus();
+        Assertions.assertNotNull(txTestMCopyOKCallCreationStatus);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus.length);
+        Assertions.assertEquals(1, txTestMCopyOKCallCreationStatus[0]);
+
+        // Check events
+        Assertions.assertEquals(1, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "OK", null));
+        Assertions.assertEquals(0, TransactionReceiptUtil.getEventCount(txTestMCopyOKCallReceipt, "ERROR", null));
+
+    }
+
 }
diff --git a/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset0toOffset0.txt b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset0toOffset0.txt
new file mode 100644
index 00000000000..21f9112adfe
--- /dev/null
+++ b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset0toOffset0.txt
@@ -0,0 +1,112 @@
+comment
+
+// CONTRACT CODE
+// Corresponds to https://eips.ethereum.org/EIPS/eip-5656 (second case on Test Cases section)
+
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.20;
+
+contract TestMCopy {
+    constructor() {}
+
+    event OK();
+    event ERROR();
+
+    function checkMCopy() external {
+        bytes32 value = 0x0101010101010101010101010101010101010101010101010101010101010101;
+        bytes32 result = getCopiedValue(value);
+
+        if (result == value) {
+            emit OK();
+        } else {
+            emit ERROR();
+        }
+    }
+
+    function getCopiedValue(bytes32 value) public pure returns (bytes32 x) {
+        assembly {
+            mstore(0, value) // Store given value at offset 0 in memory
+            mcopy(0, 0, 32)  // Use MCOPY to copy 32 bytes starting at offset 0 to offset 0 in memory
+            x := mload(0)    // Returns the word at offset 0
+        }
+    }
+
+}
+
+// DESCRIPTION
+
+This contract contains two functions: checkMCopy, and getCopiedValue.
+
+* checkMCopy simply checks the result of the memory copying against an expected value and:
+    - If returned value matches the expected one, then the OK event is emitted
+    - ERROR event is emitted otherwise.
+
+* getCopiedValue manage the memory by storing, copying and reading values as follows:
+    - First it stores a value to memory on offset 0
+    - Then uses MCOPY to copy 32 bytes starting on offset 0 to offset 0
+    - Finally it returns the word stored on offset 0
+
+// CONTRACT BYTECODE
+
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
+
+// CONTRACT CALL
+
+- checkMCopy()
+
+    8c2bcab9
+
+end
+
+# Create and fund new account
+account_new acc1 10000000
+
+# Create transaction to deploy TestMCopy contract
+transaction_build txTestMCopy
+    sender acc1
+    receiverAddress 00
+    value 0
+    data 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
+    gas 1200000
+    build
+
+# Create block to hold txTestMCopy transaction
+block_build b01
+    parent g00
+    transactions txTestMCopy
+    build
+
+# Connect block
+block_connect b01
+
+# Check b01 is best block
+assert_best b01
+
+# Check txTestMCopy succeeded
+assert_tx_success txTestMCopy
+
+# Create transaction to execute checkMCopy() method
+transaction_build txTestMCopyOKCall
+    sender acc1
+    nonce 1
+    contract txTestMCopy
+    value 0
+    data 8c2bcab9
+    gas 30000
+    build
+
+# Create block to hold txTestMCopyOKCall transaction
+block_build b02
+    parent b01
+    transactions txTestMCopyOKCall
+    gasLimit 6500000
+    build
+
+# Connect block
+block_connect b02
+
+# Check b02 is best block
+assert_best b02
+
+# Check txTestMCopyOKCall succeeded
+assert_tx_success txTestMCopyOKCall
\ No newline at end of file
diff --git a/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset32toOffset0.txt b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset32toOffset0.txt
index 153a9938f13..860cd40ac1b 100644
--- a/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset32toOffset0.txt
+++ b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying32BytesFromOffset32toOffset0.txt
@@ -1,6 +1,7 @@
 comment
 
 // CONTRACT CODE
+// Corresponds to https://eips.ethereum.org/EIPS/eip-5656 (first case on Test Cases section)
 
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.20;
@@ -24,9 +25,9 @@ contract TestMCopy {
 
     function getCopiedValue(bytes32 value) public pure returns (bytes32 x) {
         assembly {
-            mstore(32, value) // Store given value at offset 32 (word 1) in memory
-            mcopy(0, 32, 32)  // Use MCOPY to copy the value at offset 32 (word 1) to offset 0 (word 0) in memory
-            x := mload(0)     // Returns the value at offset 0 (word 0)
+            mstore(32, value) // Store given value at offset 32 in memory
+            mcopy(0, 32, 32)  // Use MCOPY to copy 32 bytes starting at offset 32 to offset 0 in memory
+            x := mload(0)     // Returns the word at offset 0
         }
     }
 
@@ -41,13 +42,13 @@ This contract contains two functions: checkMCopy, and getCopiedValue.
     - ERROR event is emitted otherwise.
 
 * getCopiedValue manage the memory by storing, copying and reading values as follows:
-    - First it stores a value to memory on word 1
-    - Then uses MCOPY to copy the value on word 1 to word 0
-    - Finally it returns the value stored on word 0
+    - First it stores a value to memory on offset 0
+    - Then uses MCOPY to copy 32 bytes starting on offset 32 to offset 0
+    - Finally it returns the word stored on offset 0
 
 // CONTRACT BYTECODE
 
-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
 
 // CONTRACT CALL
 
@@ -65,7 +66,7 @@ transaction_build txTestMCopy
     sender acc1
     receiverAddress 00
     value 0
-    data 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
+    data 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
     gas 1200000
     build
 
diff --git a/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset0toOffset1.txt b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset0toOffset1.txt
new file mode 100644
index 00000000000..9aadc4e0a46
--- /dev/null
+++ b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset0toOffset1.txt
@@ -0,0 +1,113 @@
+comment
+
+// CONTRACT CODE
+// Corresponds to https://eips.ethereum.org/EIPS/eip-5656 (fourth case on Test Cases section)
+
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.20;
+
+contract TestMCopy {
+    constructor() {}
+
+    event OK();
+    event ERROR();
+
+    function checkMCopy() external {
+        bytes32 expected = 0x0000010203040506070000000000000000000000000000000000000000000000;
+        bytes32 result = getCopiedValue();
+
+        if (result == expected) {
+            emit OK();
+        } else {
+            emit ERROR();
+        }
+    }
+
+    function getCopiedValue() public pure returns (bytes32 x) {
+        bytes32 initialValue = 0x0001020304050607080000000000000000000000000000000000000000000000;
+        assembly {
+            mstore(0, initialValue) // Initialize memory with a word at offset 0
+            mcopy(1, 0, 8)          // Use MCOPY to copy 8 bytes starting from offset 0 to offset 1 in memory
+            x := mload(0)           // Returns the word starting at offset 0
+        }
+    }
+
+}
+
+// DESCRIPTION
+
+This contract contains two functions: checkMCopy, and getCopiedValue.
+
+* checkMCopy simply checks the result of the memory copying against an expected value and:
+    - If returned value matches the expected one, then the OK event is emitted
+    - ERROR event is emitted otherwise.
+
+* getCopiedValue manage the memory by storing, copying and reading values as follows:
+    - First it stores a value to memory on offset 0
+    - Then uses MCOPY to copy 8 bytes starting on offset 0 to offset 1
+    - Finally it returns the word stored on offset 0
+
+// CONTRACT BYTECODE
+
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
+
+// CONTRACT CALL
+
+- checkMCopy()
+
+    8c2bcab9
+
+end
+
+# Create and fund new account
+account_new acc1 10000000
+
+# Create transaction to deploy TestMCopy contract
+transaction_build txTestMCopy
+    sender acc1
+    receiverAddress 00
+    value 0
+    data 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
+    gas 1200000
+    build
+
+# Create block to hold txTestMCopy transaction
+block_build b01
+    parent g00
+    transactions txTestMCopy
+    build
+
+# Connect block
+block_connect b01
+
+# Check b01 is best block
+assert_best b01
+
+# Check txTestMCopy succeeded
+assert_tx_success txTestMCopy
+
+# Create transaction to execute checkMCopy() method
+transaction_build txTestMCopyOKCall
+    sender acc1
+    nonce 1
+    contract txTestMCopy
+    value 0
+    data 8c2bcab9
+    gas 30000
+    build
+
+# Create block to hold txTestMCopyOKCall transaction
+block_build b02
+    parent b01
+    transactions txTestMCopyOKCall
+    gasLimit 6500000
+    build
+
+# Connect block
+block_connect b02
+
+# Check b02 is best block
+assert_best b02
+
+# Check txTestMCopyOKCall succeeded
+assert_tx_success txTestMCopyOKCall
\ No newline at end of file
diff --git a/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset1toOffset0.txt b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset1toOffset0.txt
new file mode 100644
index 00000000000..8b4ed86b53f
--- /dev/null
+++ b/rskj-core/src/test/resources/dsl/opcode/mcopy/testCopying8BytesFromOffset1toOffset0.txt
@@ -0,0 +1,113 @@
+comment
+
+// CONTRACT CODE
+// Corresponds to https://eips.ethereum.org/EIPS/eip-5656 (third case on Test Cases section)
+
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.20;
+
+contract TestMCopy {
+    constructor() {}
+
+    event OK();
+    event ERROR();
+
+    function checkMCopy() external {
+        bytes32 expected = 0x0102030405060708080000000000000000000000000000000000000000000000;
+        bytes32 result = getCopiedValue();
+
+        if (result == expected) {
+            emit OK();
+        } else {
+            emit ERROR();
+        }
+    }
+
+    function getCopiedValue() public pure returns (bytes32 x) {
+        bytes32 initialValue = 0x0001020304050607080000000000000000000000000000000000000000000000;
+        assembly {
+            mstore(0, initialValue) // Initialize memory with a word at offset 0
+            mcopy(0, 1, 8)          // Use MCOPY to copy 8 bytes starting from offset 1 to offset 0 in memory
+            x := mload(0)           // Returns the word starting at offset 0
+        }
+    }
+
+}
+
+// DESCRIPTION
+
+This contract contains two functions: checkMCopy, and getCopiedValue.
+
+* checkMCopy simply checks the result of the memory copying against an expected value and:
+    - If returned value matches the expected one, then the OK event is emitted
+    - ERROR event is emitted otherwise.
+
+* getCopiedValue manage the memory by storing, copying and reading values as follows:
+    - First it stores a value to memory on offset 0
+    - Then uses MCOPY to copy 8 bytes starting on offset 1 to offset 0
+    - Finally it returns the word stored on offset 0
+
+// CONTRACT BYTECODE
+
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
+
+// CONTRACT CALL
+
+- checkMCopy()
+
+    8c2bcab9
+
+end
+
+# Create and fund new account
+account_new acc1 10000000
+
+# Create transaction to deploy TestMCopy contract
+transaction_build txTestMCopy
+    sender acc1
+    receiverAddress 00
+    value 0
+    data 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
+    gas 1200000
+    build
+
+# Create block to hold txTestMCopy transaction
+block_build b01
+    parent g00
+    transactions txTestMCopy
+    build
+
+# Connect block
+block_connect b01
+
+# Check b01 is best block
+assert_best b01
+
+# Check txTestMCopy succeeded
+assert_tx_success txTestMCopy
+
+# Create transaction to execute checkMCopy() method
+transaction_build txTestMCopyOKCall
+    sender acc1
+    nonce 1
+    contract txTestMCopy
+    value 0
+    data 8c2bcab9
+    gas 30000
+    build
+
+# Create block to hold txTestMCopyOKCall transaction
+block_build b02
+    parent b01
+    transactions txTestMCopyOKCall
+    gasLimit 6500000
+    build
+
+# Connect block
+block_connect b02
+
+# Check b02 is best block
+assert_best b02
+
+# Check txTestMCopyOKCall succeeded
+assert_tx_success txTestMCopyOKCall
\ No newline at end of file