 <p>First, a general note, as stated by the <a href="http://developer.android.com/reference/android/os/AsyncTask.html" rel="nofollow">Android Docs</a>:</p> <p><code>AsyncTasks should ideally be used for short operations (a few seconds at the most). If you need to keep threads running for long periods of time, it is highly recommended you use the various APIs provided by the java.util.concurrent pacakge such as Executor, ThreadPoolExecutor and FutureTask.</code></p> <p>To answer your questions:</p> <ol> <li>Yes - you can use Async task as if it were just a background thread - an Async task is merely a wrapper of <code>Thread</code> and <code>Handler</code> that allows the thread to seamlessly communicate with the UI thread. <strong>Warning!</strong> If you plan to update the UI thread, or otherwise reference an activity or fragment in the callbacks that reference the UI thread (i.e. onProgressUpdated and/or onPostExecute) you should explicitly check that the activity or fragment is still in a state from which it can be referenced and used. For example - here's the right and wrong way to do it when launching an AsyncTask from a fragment:</li> </ol> <p>Create your task with a ref to the activity so you can do something when it's done:</p> <pre><code>private class DownloadFilesTask extends AsyncTask&lt;URL, Integer, Long&gt; { Fragment mFragment; public DownloadFilesTask(Fragment fragment){ mFragment = fragment; } </code></pre> <p>WRONG: </p> <pre><code> protected void onPostExecute(Long result) { // if the fragment has been detached, this will crash mFragment.getView().findView... } </code></pre> <p>RIGHT:</p> <pre><code> protected void onPostExecute(Long result) { if (mFragment !=null &amp;&amp; mFragment.isResumed()) ... do something on the UI thread ... } } </code></pre> <ol> <li><p>If the Activity dies while an AsyncTask is executed, it will continue to run. Using the techniques listed above, you can avoid crashes by checking the lifecycle of the context that started the task. </p></li> <li><p>Finally, if you have a very long-running operation that does not require the UI thread at all, you should look into using a <a href="http://developer.android.com/reference/android/app/Service.html" rel="nofollow">Service</a>. Here's a blurb:</p></li> </ol> <p><code>A Service is an application component representing either an application's desire to perform a longer-running operation while not interacting with the user or to supply functionality for other applications to use</code> </p>