DSM-III will be published early this year. In the first part of this article the authors describe some of the major achievements of DSM-III: the process of its development, reaching consensus on many controversial diagnostic categories and a definition of mental disorder, the provision of diagnostic criteria and a multiaxial evaluation system, and the demonstration of improved diagnostic reliability. In the second part of the article the authors present an overview of DSM-III in which they describe its departures from DSM-II and the reasons for these changes. They conclude that in the next few years there should be systematic study of DSM-III in use, so that information about its strengths and limitations can be made available to those responsible for developing DSM-IV.