 <p>There are quite a few problems here:</p> <ul> <li><code>application/models</code>, <code>application/controllers</code> and <code>application/views/scripts</code> should not be on the include path. </li> <li><code>$loader-&gt;registerNamespace('hiring');</code> should probably be <code>$loader-&gt;registerNamespace('Hiring_');</code> (although there's no sign in the code sample you've included that you are using this namespace). </li> <li><code>$loader-&gt;setFallbackAutoloader(true);</code> is probably not needed (there's no sign in the code sample you've included that you need this).</li> <li>All of the <code>Zend_Loader::loadClass</code> lines should be removed. The whole point of an autoloader is that you don't need to then require in or load classes yourself</li> <li>At least the front controller configuration should be moved to your bootstrap class</li> </ul> <p>But none of these things will affect the problem you are reporting. The standard autoloader setup will only load classes whose name can be mapped directly to the file system (by converting underscores to slashes in the path, e.g. the class <code>Zend_Db_Table</code> would live at <code>library/Zend/Db/Table.php</code>). The class <code>Application_Model_Hiring</code> does not fit this model, if you want to use this naming scheme as well you need to also setup a resource autoloader, which maps just the last part of the class name to some pre-defined sub-folders within <code>application/</code>.</p> <p>Add the following method to your bootstrap class:</p> <pre><code>protected function _initAutoloader() { $autoloader = Zend_Loader_Autoloader::getInstance(); $autoloader-&gt;registerNamespace('Hiring_'); $applicationResourceAutoloader = new Zend_Loader_Autoloader_Resource(array( 'basePath' =&gt; APPLICATION_PATH, 'namespace' =&gt; 'Application' )); $autoloader-&gt;pushAutoloader($applicationResourceAutoloader); return $autoloader; } </code></pre> <p>This setups up the standard autoloader (<code>$autoloader = Zend_Loader_Autoloader::getInstance();</code>), which will autoload the Zend Framework classes. It then registers a namespace 'Hiring', which you only need if you are including classes that start with this name in your library folder.</p> <p>It then creates a separate resource autoloader with the namespace 'Application', which will load classes from the application folder, including models. Assuming the class <code>Application_Model_Hiring</code> is defined at <code>application/models/Hiring.php</code> it should then work.</p> <p>More info at <a href="http://framework.zend.com/manual/1.12/en/zend.loader.autoloader-resource.html" rel="nofollow">http://framework.zend.com/manual/1.12/en/zend.loader.autoloader-resource.html</a></p>