diff --git a/README.md b/README.md
index b05d5060f..15532ecec 100644
--- a/README.md
+++ b/README.md
@@ -102,6 +102,19 @@ The task definition file can be updated prior to deployment with the new contain
         wait-for-service-stability: true
 ```
 
+If you're using CloudFormation tools such as AWS CDK, Serverless Framework, or others to construct your task definition, you can directly pass the ARN of the task definition. For example:
+```yaml
+    - name: Deploy Amazon ECS task definition
+      uses: aws-actions/amazon-ecs-deploy-task-definition@v1
+      with:
+        task-definition: arn:aws:ecs:<region>:<aws_account_id>:task-definition/<task_definition_name>:<revision_number>
+        service: my-service
+        cluster: my-cluster
+        wait-for-service-stability: true
+
+```
+
+
 ## Credentials and Region
 
 This action relies on the [default behavior of the AWS SDK for Javascript](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/setting-credentials-node.html) to determine AWS credentials and region.
diff --git a/index.js b/index.js
index ff5f57c93..ab7d3724b 100644
--- a/index.js
+++ b/index.js
@@ -262,7 +262,7 @@ async function run() {
     });
 
     // Get inputs
-    const taskDefinitionFile = core.getInput('task-definition', { required: true });
+    const taskDefinitionContent = core.getInput('task-definition', { required: true });
     const service = core.getInput('service', { required: false });
     const cluster = core.getInput('cluster', { required: false });
     const waitForService = core.getInput('wait-for-service-stability', { required: false });
@@ -276,23 +276,35 @@ async function run() {
     const desiredCount = parseInt((core.getInput('desired-count', {required: false})));
 
 
-    // Register the task definition
-    core.debug('Registering the task definition');
-    const taskDefPath = path.isAbsolute(taskDefinitionFile) ?
-      taskDefinitionFile :
-      path.join(process.env.GITHUB_WORKSPACE, taskDefinitionFile);
-    const fileContents = fs.readFileSync(taskDefPath, 'utf8');
-    const taskDefContents = maintainValidObjects(removeIgnoredAttributes(cleanNullKeys(yaml.parse(fileContents))));
-    let registerResponse;
-    try {
-      registerResponse = await ecs.registerTaskDefinition(taskDefContents).promise();
-    } catch (error) {
-      core.setFailed("Failed to register task definition in ECS: " + error.message);
-      core.debug("Task definition contents:");
-      core.debug(JSON.stringify(taskDefContents, undefined, 4));
-      throw(error);
-    }
-    const taskDefArn = registerResponse.taskDefinition.taskDefinitionArn;
+    let taskDefArn = null;
+
+    // Of taskDefContent starts with arn: then we assume it is a task definition ARN
+    if (taskDefinitionContent.startsWith("arn:")) {
+      taskDefArn = taskDefinitionContent;
+
+    // 
+    // Else we assume it is a task definition file
+    } else {
+      const taskDefinitionFile = taskDefinitionContent;
+
+      core.debug('Registering the task definition');
+      const taskDefPath = path.isAbsolute(taskDefinitionFile) ?
+        taskDefinitionFile :
+        path.join(process.env.GITHUB_WORKSPACE, taskDefinitionFile);
+      const fileContents = fs.readFileSync(taskDefPath, 'utf8');
+      const taskDefContents = maintainValidObjects(removeIgnoredAttributes(cleanNullKeys(yaml.parse(fileContents))));
+      let registerResponse;
+      try {
+        registerResponse = await ecs.registerTaskDefinition(taskDefContents).promise();
+      } catch (error) {
+        core.setFailed("Failed to register task definition in ECS: " + error.message);
+        core.debug("Task definition contents:");
+        core.debug(JSON.stringify(taskDefContents, undefined, 4));
+        throw(error);
+      }
+      taskDefArn = registerResponse.taskDefinition.taskDefinitionArn;
+    } 
+    
     core.setOutput('task-definition-arn', taskDefArn);
 
     // Update the service with the new task definition
diff --git a/index.test.js b/index.test.js
index ba4f6ac97..e70c5221f 100644
--- a/index.test.js
+++ b/index.test.js
@@ -16,6 +16,7 @@ const mockEcsWaiter = jest.fn();
 const mockCodeDeployCreateDeployment = jest.fn();
 const mockCodeDeployGetDeploymentGroup = jest.fn();
 const mockCodeDeployWaiter = jest.fn();
+
 let config = {
   region: 'fake-region',
 };
@@ -151,6 +152,20 @@ describe('Deploy to ECS', () => {
         });
     });
 
+    test('uses task definition ARN if taskDefinitionContent starts with arn:', async () => {
+      core.getInput = jest
+          .fn()
+          .mockReturnValueOnce('arn:aws:ecs:region:account-id:task-definition/task-name:task-revision') // task-definition
+          .mockReturnValueOnce('service-456') // service
+          .mockReturnValueOnce('cluster-789'); // cluster
+  
+      await run();
+      
+      expect(core.setFailed).toHaveBeenCalledTimes(0);
+      expect(mockEcsRegisterTaskDef).toHaveBeenCalledTimes(0);  // Importante, não deve chamar a função de registro
+      expect(core.setOutput).toHaveBeenNthCalledWith(1, 'task-definition-arn', 'arn:aws:ecs:region:account-id:task-definition/task-name:task-revision');
+    });
+
     test('registers the task definition contents and updates the service', async () => {
         await run();
         expect(core.setFailed).toHaveBeenCalledTimes(0);