Regression testing is a process that executes subset of tests that have already been conducted to ensure that changes have not propagated unintended side effects. Test case prioritization aims at reordering the regression test suit based on certain criteria, so that the test cases with higher priority can be executed first rather than those with lower priority. In this paper, a new approach for test case prioritization has been proposed which is based on a module-coupling effect that considers the module-coupling value for the purpose of prioritizing the modules in the software so that critical modules can be identified which in turn will find the prioritized set of test cases. In this way there will be high percentage of detecting critical errors that have been propagated to other modules due to any change in a module. The proposed approach has been evaluated with a case study of software consisting of ten modules.