This article shows the relationship between know-how and conceptual ability with particular reference to professional education. It is argued that although concept mastery is necessary to expert performance, it is not sufficient. Starting with Geach's account of concepts, distinctions are made between concept acquisition and concept mastery. An outline of the transition from concept acquisition to concept mastery is offered which stresses the importance of learning in operational conditions in order to achieve expert performance, which itself implies concept mastery. Context-sensitive aspects of concept mastery in the form of "activity concepts" (Luntley) are considered and their importance recognised. A detailed critique of the non-propositional intellectualist account of know-how offered by Bengson and Moffett is made, and the implications of the article's position for the conduct of professional education, along the lines of Germany's Dual System, are set out.