I posted about this a couple of weeks ago but didn''t get much response so I thought I''d try again. when you create a subclass of Test::Unit::TestCase, e.g. PersonTest (for model Person), the tests in that class get run automatically whenever the file is loaded. so far so good. Let''s say I then create a Manager class which subclasses Person. I want ManagerTest to extend PersonTest. However, because of the automatic running I mentioned previously, if you try to load manager_test.rb, you end up running both PersonTest and ManagerTest. This may not sound like a big problem but I have 3 levels of subclasses on about 6 core classes, so you can imagine how long ''rake test_units'' takes to run! The only way round it that I''ve found is to create a subclass of TestCase for each model which contains test for the functionality in the parent class and it''s derived class, but that totally violates the DRY principle. IMHO the TestCase for the parent should test the parent functionality, and subclassed TestCases should test the functionality of the subclasses. this problem is only going to get worse as I add more parent and sub-classes, so could someone please save what little hair I have left and suggest a workaround? thanks for reading al