In recent years there has been a ground swell of interest in the application of evolutionary theory to issues in psychopathology (Nesse and Williams, 1995; Stevens and Price, 1996; McGuire and Troisi, 1998). Much of this work has been aimed at finding adaptationist explanations for a variety of mental disorders ranging from phobias to depression to schizophrenia. There has, however, been relatively little discussion of the implications that the theories proposed by evolutionary psychologists might have for the classification of mental disorders. This is the theme we propose to explore. We'll begin, in section 1, by providing a brief overview of the account of the mind advanced by evolutionary psychologists. In section 2 we'll explain why issues of taxonomy are important and why the dominant approach to the classification of mental disorders is radically and alarmingly unsatisfactory. We will also indicate why we think an alternative approach, based on theories in evolutionary psychology, is particularly promising. In section 3 we'll try to illustrate some of the virtues of the evolutionary-psychological approach to classification. The discussion in section 3 will highlight a quite fundamental distinction between those disorders that arise from the malfunction of a component of the mind and those that can be traced to the fact that our minds must now function in environments that are very different from the environments in which they evolved.