In this article we provide a tutorial review of various theoretical issues that surround executive function research from the perspective of cognitive psychology, focusing on issues that have important implications for clinical assessment of executive functioning. We first discuss theoretical and clinical reasons for the importance of understanding executive functions and then point out some serious problems with the common practice of relying exclusively on complex neuropsychological tests, such as the Wisconsin Card Sorting Test and the Tower of Hanoi, as general measures of executive functioning. We then briefly present a recent individual differences study of executive functions conducted in our laboratory that attempted to overcome certain limitations associated with the more typical approach. On the basis of the theoretical issues discussed and the results from our study, we offer some concrete suggestions and recommendations for the measurement and assessment of executive functions in clinical settings.