diff --git a/pom.xml b/pom.xml
index b410baa..7da0af6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -47,6 +47,13 @@
             <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
             <version>2.1.0</version>
         </dependency>
+
+        <!-- Dependências para testes com JUnit 5 e Mockito -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/test/java/com/example/service/UserServiceTest.java b/src/test/java/com/example/service/UserServiceTest.java
new file mode 100644
index 0000000..ef9231a
--- /dev/null
+++ b/src/test/java/com/example/service/UserServiceTest.java
@@ -0,0 +1,33 @@
+package com.example.service;
+
+import com.example.exception.UserNotFoundException;
+import com.example.repository.UserRepository;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class UserServiceTest {
+
+    @Mock
+    private UserRepository userRepository;
+
+    @InjectMocks
+    private UserService userService;
+
+    @Test
+    void deleteUser_shouldThrowException_whenUserNotFound() {
+        Long userId = 1L;
+        when(userRepository.existsById(userId)).thenReturn(false);
+
+        assertThrows(UserNotFoundException.class, () -> userService.deleteUser(userId));
+
+        verify(userRepository, never()).deleteById(anyLong());
+    }
+}