diff --git a/makefile b/makefile
index 1f15f75..425a192 100644
--- a/makefile
+++ b/makefile
@@ -35,15 +35,28 @@ $(program_obj_filesobj_files): %.o: %.c
 # --------------------------
 # Unit Tests
 # --------------------------
-unitTests:
-	echo "needs to be implemented"
+tets_sources = test_stack.c stack.c
+test_objects = $(test_sources:.c=.o)
+
+test_runner: $(test_objects)
+	$(CC) $(FLAGS) $^ -o $@
+
+unitTests: test_runner
+	@echo "============================="
+	@echo "Running Stack Unit Tests..."
+	@echo "============================="
+	./test_runner
+	@echo "============================="
+	@echo "Stack Unit Tests Finished."
+	@echo "============================="
+
 
 # --------------------------
 # Clean
 # --------------------------
 clean:
 ifeq ($(OS),Windows_NT)
-	del /f *.o doble
+	del /f *.o doble test_runner
 else
-	rm -f *.o doble
+	rm -f *.o doble test_runner
 endif
\ No newline at end of file
diff --git a/test_stack.c b/test_stack.c
index b0579e9..7acb6e9 100644
--- a/test_stack.c
+++ b/test_stack.c
@@ -4,29 +4,138 @@
 
 void test_on_empty_stack(void)
 {
-    StackNode *stack = malloc(sizeof(StackNode));
+    char *status_a = "leer";
+    char *status_b = "leer";
+    StackNode *stack = NULL;
 
     StackNode *a = pop(stack);
+    void* b = top(stack);
+
+
+    if (a == NULL)
+    {
+        status_a = "PASSED";
+    }
+    else status_a = "FAILED";
+    
+    if (b == NULL)
+    {
+        status_b = "PASSED";
+    }
+    else status_b = "FAILED";
+
+    printf("Test on empty stack in pop: %s - Expected: NULL, Was: %p\n",status_a, (void*)a);
+    printf("Test on empty stack in top: %s - Expected: NULL, Was: %p\n",status_b, b);
 
-    printf("%s", stack);
 }
 
 void test_push(void)
 {
-    int *test_value = malloc(sizeof(int));
-    test_value = (int*)1;
-    StackNode *stack = malloc(sizeof(StackNode));
+    int a[3] = 0;
+    StackNode *stack = NULL;
 
-    StackNode *new_stack = push(stack, test_value);
+    for (int i = 1; i < 4; i++)
+    {
+        int *var_push = malloc(sizeof(int));
 
+        if (var_push == NULL) 
+        {
+            printf("Error in allocating memory in test_push!\n");
+            exit(EXIT_FAILURE);
+        }
+
+        *var_push = i;
+        stack = push(stack, var_push);
+
+        void *top_data = top(stack);
+        if (top_data != NULL && *(int*)top_data == i) {
+            a[i-1] = 1; 
+        } else {
+            a[i-1] = 0; 
+        }
+    }
     
+    if (a[0] == 1 && a[1] == 1 && a[2] == 1)
+    {
+        printf("Test push: SUCCEESS!\n");
+    }
+    
+    else printf("Test pus: FAILED - Expected: all 1, Was: %d, %d, %d\n", a[0], a[1], a[2]);
+
+    stack = clearStack(stack);
+}
+
+void test_pop(void)
+{
+    StackNode *stack = NULL;
+    int *var_push = malloc(sizeof(int));
+
+    if (var_push == NULL) 
+    {
+        fprintf(stderr, "Error in allocating memory in test_pop! Exiting.\n");
+        exit(EXIT_FAILURE);
+    }
+
+    *var_push = 1;
+    stack = push(stack, var_push);
+    stack = pop(stack);
+
+    if (stack == NULL) printf("Test pop: SUCCESS!\n");
+
+    else printf("Test pop: FAIL! - Stack is not empty! Head: %p\n", (void*)stack);
+
+    stack = clearStack(stack);
+}
+
+void test_top(void)
+{
+    StackNode *stack = NULL;
+    int *var_push = malloc(sizeof(int));
+    *var_push = 1;
+    stack = push(stack, var_push);
+    void *b = top(stack);
+
+    if (b != 0 && *(int*)b == 1) printf("Test top: SUCCESS!\n");
+
+    else printf("Test top: FAIL! - Expected 1, was %p\n", b);
+
+    stack = clearStack(stack);
+}
+
+void test_clearStack(void)
+{
+    StackNode *stack = NULL;
+
+    for (int i = 1; i < 4; i++)
+    {
+        int *var_push = malloc(sizeof(int));
+
+        if (var_push == NULL) 
+        {
+            fprintf(stderr, "Error in allocating memory in test_clearStack! Exiting.\n");
+            exit(EXIT_FAILURE); 
+        }
+
+        *var_push = i;
+        stack = push(stack, var_push);
+    }
+
+    stack = clearStack(stack);
+    void *a = top(stack);
+    if (a == NULL) printf("Test clear: SUCESS!\n");
+
+    else printf("Test clear: FAILED! - Expected: NULL, Was:%p\n", a);
 }
 
 int main()
 {
     printf("============================\nStack Tests\n============================\n");
 
-    test_on_empty_stack;
+    test_on_empty_stack();
+    test_push();
+    test_pop();
+    test_top();
+    test_clearStack();
 
     return EXIT_SUCCESS;
 }
\ No newline at end of file