<p>If so how?  </p>

<p>Did you roll your own with jQuery or use the Microsoft AJAX toolkit?</p>

<p>Did you create a webservice or call an action?</p>

<hr>

<p><strong>EDIT</strong> : Please note that this question was asked before Microsoft announced that they were going to bundle jQuery in with VS/ASP.NET MVC.  I think there is less of a discussion around this topic now and the answer would now almost always be 'use jQuery'. IainMH 11th Feb 2009</p>

[{'answer_id': 40120, 'author': 'Matt Hinze', 'author_id': 2676, 'author_profile': 'https://Stackoverflow.com/users/2676', 'pm_score': 3, 'selected': True, 'text': '<p>jQuery, action, return JSON.</p>\n\n<p><a href="http://devlicio.us/blogs/mike_nichols/archive/2008/05/25/jquery-cascade-cascading-values-from-forms.aspx" rel="nofollow noreferrer">http://devlicio.us/blogs/mike_nichols/archive/2008/05/25/jquery-cascade-cascading-values-from-forms.aspx</a></p>\n'}, {'answer_id': 48453, 'author': 'Iain Holder', 'author_id': 1122, 'author_profile': 'https://Stackoverflow.com/users/1122', 'pm_score': 2, 'selected': False, 'text': '<p>I\'ve spent the past day or two getting @<a href="https://stackoverflow.com/questions/39735/have-you-got-a-cascadingdropdown-working-with-aspnet-mvc#40120">Matt Hinze\'s answer</a> to work.  It works well.  jQuery is the prefferred method of doing AJAX in the forthcoming <a href="http://www.manning.com/palermo/" rel="nofollow noreferrer">ASP.NET MVC In Action</a> book from Manning.  You can get a pdf of a free preview chapter on AJAX in MVC <a href="http://www.manning.com/palermo/palermo_meapch9_sample.pdf" rel="nofollow noreferrer">here</a>.</p>\n\n<p>However, <a href="http://www.aspworkshops.com/" rel="nofollow noreferrer">Stephen Walther</a> in his excellent <a href="http://weblogs.asp.net/stephenwalther/archive/tags/Tips/default.aspx" rel="nofollow noreferrer">ASP.NET Tip series</a> has just blogged about creating cascading dropdowns in <a href="http://weblogs.asp.net/stephenwalther/archive/2008/09/06/asp-net-mvc-tip-41-creating-cascading-dropdown-lists-with-ajax.aspx" rel="nofollow noreferrer">Tip #41</a>.</p>\n'}, {'answer_id': 2935708, 'author': 'Raj Kaimal', 'author_id': 222170, 'author_profile': 'https://Stackoverflow.com/users/222170', 'pm_score': 2, 'selected': False, 'text': '<p>CascadingDropDown jQuery Plugin for ASP.NET MVC</p>\n\n<p><a href="http://weblogs.asp.net/rajbk/archive/2010/05/20/cascadingdropdown-jquery-plugin-for-asp-net-mvc.aspx" rel="nofollow noreferrer">http://weblogs.asp.net/rajbk/archive/2010/05/20/cascadingdropdown-jquery-plugin-for-asp-net-mvc.aspx</a></p>\n'}, {'answer_id': 3264058, 'author': 'LiamGu', 'author_id': 147145, 'author_profile': 'https://Stackoverflow.com/users/147145', 'pm_score': 0, 'selected': False, 'text': '<p><a href="http://blog.noma.li/2010/03/autopostback-and-cascading-drop-downs-in-asp-net-mvc-and-jquery/" rel="nofollow noreferrer">http://blog.noma.li/2010/03/autopostback-and-cascading-drop-downs-in-asp-net-mvc-and-jquery/</a></p>\n'}]
['https://Stackoverflow.com/questions/39735', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/1122/']