This paper describes how the expert-performance perspective differs from the common-sense view of professional ability and how this approach can be applied to the study of professional interpreting. The expert-performance approach is first introduced with findings from many traditional domains of expertise, such as chess, music, medicine, and sports. Most importantly, expert performance is shown to be primarily acquired through the engagement in designed training activities, namely deliberate practice. The second part of the paper briefly discusses earlier research on expert interpreting motivated by more traditional views of expertise in interpreting. Finally, the expert-performance approach is applied to the study of superior interpreting performance and potential studies of superior interpreting under representative conditions are outlined.