diff --git a/src/test/java/de/unistuttgart/iste/meitrex/assignment_service/service/AssignmentServiceTest.java b/src/test/java/de/unistuttgart/iste/meitrex/assignment_service/service/AssignmentServiceTest.java
new file mode 100644
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--- /dev/null
+++ b/src/test/java/de/unistuttgart/iste/meitrex/assignment_service/service/AssignmentServiceTest.java
@@ -0,0 +1,123 @@
+package de.unistuttgart.iste.meitrex.assignment_service.service;
+
+import de.unistuttgart.iste.meitrex.assignment_service.persistence.entity.AssignmentEntity;
+import de.unistuttgart.iste.meitrex.assignment_service.persistence.mapper.AssignmentMapper;
+import de.unistuttgart.iste.meitrex.assignment_service.persistence.repository.AssignmentRepository;
+import de.unistuttgart.iste.meitrex.assignment_service.validation.AssignmentValidator;
+import de.unistuttgart.iste.meitrex.common.dapr.TopicPublisher;
+import de.unistuttgart.iste.meitrex.common.event.ContentChangeEvent;
+import de.unistuttgart.iste.meitrex.common.event.CrudOperation;
+import de.unistuttgart.iste.meitrex.common.exception.IncompleteEventMessageException;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.modelmapper.ModelMapper;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+public class AssignmentServiceTest {
+
+    private final AssignmentRepository assignmentRepository = Mockito.mock(AssignmentRepository.class);
+    private final AssignmentMapper assignmentMapper = new AssignmentMapper(new ModelMapper());
+    private final AssignmentValidator assignmentValidator = new AssignmentValidator();
+    private final TopicPublisher topicPublisher = Mockito.mock(TopicPublisher.class);
+
+    private final AssignmentService assignmentService = new AssignmentService(assignmentRepository, assignmentMapper, assignmentValidator, topicPublisher);
+
+    @Test
+    void deleteAssignmentIfContentIsDeletedValidTest() {
+        // init
+        final UUID assessmentId = UUID.randomUUID();
+
+        final AssignmentEntity assignmentEntity = AssignmentEntity.builder()
+                .assessmentId(assessmentId)
+                .exercises(new ArrayList<>())
+                .build();
+
+        final ContentChangeEvent contentChangeEvent = ContentChangeEvent.builder()
+                .contentIds(List.of(assessmentId))
+                .operation(CrudOperation.DELETE)
+                .build();
+
+        //mock repository
+        when(assignmentRepository.findAllById(contentChangeEvent.getContentIds())).thenReturn(List.of(assignmentEntity));
+
+        // invoke method under test
+        assertDoesNotThrow(() -> assignmentService.deleteAssignmentIfContentIsDeleted(contentChangeEvent));
+        verify(assignmentRepository, times(1)).deleteAllById(any());
+    }
+
+
+    @Test
+    void deleteAssignmentIfContentIsDeletedWithNoAssignmentsTest() {
+        //init
+        UUID assessmentId = UUID.randomUUID();
+
+        ContentChangeEvent contentChangeEvent = ContentChangeEvent.builder()
+                .contentIds(List.of(assessmentId))
+                .operation(CrudOperation.DELETE)
+                .build();
+
+        //mock repository
+        when(assignmentRepository.findAllById(contentChangeEvent.getContentIds())).thenReturn(new ArrayList<AssignmentEntity>());
+
+        // invoke method under test
+        assertDoesNotThrow(() -> assignmentService.deleteAssignmentIfContentIsDeleted(contentChangeEvent));
+        verify(assignmentRepository, times(1)).deleteAllById(any());
+    }
+
+    @Test
+    void deleteAssignmentIfContentIsDeletedInvalidEventsTest() {
+        //init
+        UUID assessmentId = UUID.randomUUID();
+
+        ContentChangeEvent emptyListDto = ContentChangeEvent.builder()
+                .contentIds(List.of())
+                .operation(CrudOperation.DELETE)
+                .build();
+
+        ContentChangeEvent nullListDto = ContentChangeEvent.builder()
+                .contentIds(null)
+                .operation(CrudOperation.DELETE)
+                .build();
+
+        ContentChangeEvent nullOperationDto = ContentChangeEvent.builder()
+                .contentIds(List.of(assessmentId))
+                .operation(null)
+                .build();
+
+        ContentChangeEvent creationEvent = ContentChangeEvent.builder()
+                .contentIds(List.of(assessmentId))
+                .operation(CrudOperation.CREATE)
+                .build();
+
+        ContentChangeEvent updateEvent = ContentChangeEvent.builder()
+                .contentIds(List.of(assessmentId))
+                .operation(CrudOperation.UPDATE)
+                .build();
+
+        List<ContentChangeEvent> events = List.of(emptyListDto, creationEvent, updateEvent);
+        List<ContentChangeEvent> errorEvents = List.of(nullListDto, nullOperationDto);
+
+        for (ContentChangeEvent event : events) {
+            // invoke method under test
+            assertDoesNotThrow(() -> assignmentService.deleteAssignmentIfContentIsDeleted(event));
+            verify(assignmentRepository, never()).findAllById(any());
+            verify(assignmentRepository, never()).deleteAllById(any());
+        }
+
+        for (ContentChangeEvent errorEvent : errorEvents) {
+            // invoke method under test
+            assertThrows(IncompleteEventMessageException.class, () -> assignmentService.deleteAssignmentIfContentIsDeleted(errorEvent));
+            verify(assignmentRepository, never()).findAllById(any());
+            verify(assignmentRepository, never()).deleteAllById(any());
+        }
+
+    }
+}