diff --git a/src/main/java/io/aiven/connect/jdbc/JdbcSinkConnector.java b/src/main/java/io/aiven/connect/jdbc/JdbcSinkConnector.java
index 4c84a82e..caa12537 100644
--- a/src/main/java/io/aiven/connect/jdbc/JdbcSinkConnector.java
+++ b/src/main/java/io/aiven/connect/jdbc/JdbcSinkConnector.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
+ * Copyright 2024 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
  * Copyright 2016 Confluent Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -68,8 +68,10 @@ public ConfigDef config() {
 
     @Override
     public Config validate(final Map<String, String> connectorConfigs) {
-        // TODO cross-fields validation here: pkFields against the pkMode
-        return super.validate(connectorConfigs);
+        final Config config = super.validate(connectorConfigs);
+
+        JdbcSinkConfig.validatePKModeAgainstPKFields(config);
+        return config;
     }
 
     @Override
diff --git a/src/main/java/io/aiven/connect/jdbc/sink/JdbcSinkConfig.java b/src/main/java/io/aiven/connect/jdbc/sink/JdbcSinkConfig.java
index 04be94c1..2be238a6 100644
--- a/src/main/java/io/aiven/connect/jdbc/sink/JdbcSinkConfig.java
+++ b/src/main/java/io/aiven/connect/jdbc/sink/JdbcSinkConfig.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
+ * Copyright 2024 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
  * Copyright 2016 Confluent Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -29,8 +29,10 @@
 import java.util.TimeZone;
 import java.util.stream.Collectors;
 
+import org.apache.kafka.common.config.Config;
 import org.apache.kafka.common.config.ConfigDef;
 import org.apache.kafka.common.config.ConfigException;
+import org.apache.kafka.common.config.ConfigValue;
 
 import io.aiven.connect.jdbc.config.JdbcConfig;
 import io.aiven.connect.jdbc.util.StringUtils;
@@ -437,4 +439,65 @@ public static void main(final String... args) {
         System.out.println();
         System.out.println(CONFIG_DEF.toEnrichedRst());
     }
+
+    public static void validatePKModeAgainstPKFields(final Config config) {
+        // Collect all configuration values
+        final Map<String, ConfigValue> configValues = config.configValues().stream()
+                .collect(Collectors.toMap(ConfigValue::name, v -> v));
+
+        final ConfigValue pkModeConfigValue = configValues.get(JdbcSinkConfig.PK_MODE);
+        final ConfigValue pkFieldsConfigValue = configValues.get(JdbcSinkConfig.PK_FIELDS);
+
+        if (pkModeConfigValue == null || pkFieldsConfigValue == null) {
+            return; // If either pkMode or pkFields are not configured, there's nothing to validate
+        }
+
+        final String pkMode = (String) pkModeConfigValue.value();
+        final List<String> pkFields = (List<String>) pkFieldsConfigValue.value();
+
+        if (pkMode == null) {
+            return; // If pkMode is null, skip validation
+        }
+
+        switch (pkMode.toLowerCase()) {
+            case "none":
+                validateNoPKFields(pkFieldsConfigValue, pkFields);
+                break;
+            case "kafka":
+                validateKafkaPKFields(pkFieldsConfigValue, pkFields);
+                break;
+            case "record_key":
+            case "record_value":
+                validatePKFieldsRequired(pkFieldsConfigValue, pkFields);
+                break;
+            default:
+                pkFieldsConfigValue.addErrorMessage("Invalid pkMode value: " + pkMode);
+                break;
+        }
+    }
+
+    private static void validateNoPKFields(final ConfigValue pkFieldsConfigValue, final List<String> pkFields) {
+        if (pkFields != null && !pkFields.isEmpty()) {
+            pkFieldsConfigValue.addErrorMessage(
+                    "Primary key fields should not be set when pkMode is 'none'."
+            );
+        }
+    }
+
+    private static void validateKafkaPKFields(final ConfigValue pkFieldsConfigValue, final List<String> pkFields) {
+        if (pkFields == null || pkFields.size() != 3) {
+            pkFieldsConfigValue.addErrorMessage(
+                    "Primary key fields must be set with three fields "
+                            + "(topic, partition, offset) when pkMode is 'kafka'."
+            );
+        }
+    }
+
+    private static void validatePKFieldsRequired(final ConfigValue pkFieldsConfigValue, final List<String> pkFields) {
+        if (pkFields == null || pkFields.isEmpty()) {
+            pkFieldsConfigValue.addErrorMessage(
+                    "Primary key fields must be set when pkMode is 'record_key' or 'record_value'."
+            );
+        }
+    }
 }
diff --git a/src/test/java/io/aiven/connect/jdbc/sink/JdbcSinkConfigTest.java b/src/test/java/io/aiven/connect/jdbc/sink/JdbcSinkConfigTest.java
index b4e7527f..990f1e64 100644
--- a/src/test/java/io/aiven/connect/jdbc/sink/JdbcSinkConfigTest.java
+++ b/src/test/java/io/aiven/connect/jdbc/sink/JdbcSinkConfigTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
+ * Copyright 2024 Aiven Oy and jdbc-connector-for-apache-kafka project contributors
  * Copyright 2016 Confluent Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -20,13 +20,18 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import org.apache.kafka.common.config.Config;
 import org.apache.kafka.common.config.ConfigException;
 
+import io.aiven.connect.jdbc.JdbcSinkConnector;
+
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.assertj.core.api.Assertions.entry;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class JdbcSinkConfigTest {
 
@@ -74,4 +79,84 @@ public void shouldThrowExceptionForEmptyMappingFormat() {
             .isInstanceOf(ConfigException.class);
     }
 
+    @Test
+    public void shouldValidatePKModeNoneWithPKFieldsSet() {
+        final Map<String, String> props = new HashMap<>();
+        props.put(JdbcSinkConfig.CONNECTION_URL_CONFIG, "jdbc://localhost");
+        props.put(JdbcSinkConfig.PK_MODE, "none");
+        props.put(JdbcSinkConfig.PK_FIELDS, "id");
+
+        final Config config = new JdbcSinkConnector().validate(props);
+
+        assertTrue(config.configValues().stream().anyMatch(cv -> cv.errorMessages().size() > 0));
+        assertTrue(config.configValues().stream()
+                .filter(cv -> cv.name().equals(JdbcSinkConfig.PK_FIELDS))
+                .flatMap(cv -> cv.errorMessages().stream())
+                .anyMatch(msg -> msg.contains("Primary key fields should not be set when pkMode is 'none'")));
+    }
+
+    @Test
+    public void shouldValidatePKModeKafkaWithInvalidPKFields() {
+        final Map<String, String> props = new HashMap<>();
+        props.put(JdbcSinkConfig.CONNECTION_URL_CONFIG, "jdbc://localhost");
+        props.put(JdbcSinkConfig.PK_MODE, "kafka");
+        props.put(JdbcSinkConfig.PK_FIELDS, "topic,partition");
+
+        final Config config = new JdbcSinkConnector().validate(props);
+
+        assertTrue(config.configValues().stream().anyMatch(cv -> cv.errorMessages().size() > 0));
+        assertTrue(config.configValues().stream()
+                .filter(cv -> cv.name().equals(JdbcSinkConfig.PK_FIELDS))
+                .flatMap(cv -> cv.errorMessages().stream())
+                .anyMatch(msg -> msg.contains(
+                        "Primary key fields must be set with three fields "
+                                + "(topic, partition, offset) when pkMode is 'kafka'"
+                )));
+    }
+
+    @Test
+    public void shouldValidatePKModeRecordKeyWithNoPKFields() {
+        final Map<String, String> props = new HashMap<>();
+        props.put(JdbcSinkConfig.CONNECTION_URL_CONFIG, "jdbc://localhost");
+        props.put(JdbcSinkConfig.PK_MODE, "record_key");
+
+        final Config config = new JdbcSinkConnector().validate(props);
+
+        assertTrue(config.configValues().stream().anyMatch(cv -> cv.errorMessages().size() > 0));
+        assertTrue(config.configValues().stream()
+                .filter(cv -> cv.name().equals(JdbcSinkConfig.PK_FIELDS))
+                .flatMap(cv -> cv.errorMessages().stream())
+                .anyMatch(msg -> msg.contains(
+                        "Primary key fields must be set when pkMode is 'record_key' or 'record_value'"
+                )));
+    }
+
+    @Test
+    public void shouldValidatePKModeRecordValueWithNoPKFields() {
+        final Map<String, String> props = new HashMap<>();
+        props.put(JdbcSinkConfig.CONNECTION_URL_CONFIG, "jdbc://localhost");
+        props.put(JdbcSinkConfig.PK_MODE, "record_value");
+
+        final Config config = new JdbcSinkConnector().validate(props);
+
+        assertTrue(config.configValues().stream().anyMatch(cv -> cv.errorMessages().size() > 0));
+        assertTrue(config.configValues().stream()
+                .filter(cv -> cv.name().equals(JdbcSinkConfig.PK_FIELDS))
+                .flatMap(cv -> cv.errorMessages().stream())
+                .anyMatch(msg -> msg.contains(
+                        "Primary key fields must be set when pkMode is 'record_key' or 'record_value'"
+                )));
+    }
+
+    @Test
+    public void shouldValidateValidPKModeAndPKFields() {
+        final Map<String, String> props = new HashMap<>();
+        props.put(JdbcSinkConfig.CONNECTION_URL_CONFIG, "jdbc://localhost");
+        props.put(JdbcSinkConfig.PK_MODE, "record_key");
+        props.put(JdbcSinkConfig.PK_FIELDS, "id");
+
+        final Config config = new JdbcSinkConnector().validate(props);
+
+        assertFalse(config.configValues().stream().allMatch(cv -> cv.errorMessages().size() > 0));
+    }
 }