UML models focus primarily on the definition of system structure and behaviour, but provide only limited means for describing test objectives and test procedures. However, with the approach towards system engineering with automated code generation, the need for solid conformance testing has increased. In June 2001, an OMG Request For Proposal (RFP) on an UML2.0 Testing Profile (UTP) has been initiated. This RFP solicits proposals for a UML2.0 profile, which enables the specification of tests for structural and behavioural aspects of computational UML models, and which is capable to inter-operate with existing test technologies for black box testing. This paper discusses different approaches for testing with UML and discusses the ongoing work of the Testing Profile. Special emphasize is laid on the mapping of UML2.0 testing concepts to the standardized Testing and Test Control Notation (TTCN-3).