In this paper we present a model-based testing approach that aims at identifying, automating and deriving functional test cases in whole or in part from UML models that describe some aspects of the system under test. Our approach provides a considerable reduction of the effort on the test generation, increasing the effectiveness of the tests, shortening the testing cycle, and avoiding tedious and error-prone editing of a suite of hand-crafted tests. Finally, we present a case study to demonstrate the practicality and usefulness of the proposed approach.