A diagnosis of schizoaffective disorder is frequently used to describe a psychotic person with significant symptoms of depression and/or mania. The word schizoaffective was introduced by Jacob Kasanin in 1933 and has appeared in all editions of the DSM since 1952. However, the current DSM-IV-TR diagnosis of schizoaffective disorder is not reliable and is of limited clinical utility. The validity is built primarily on the prediction of course and outcome and on emerging findings from genetic and neurobiological studies. This review of the current status of schizoaffective disorder concludes with several suggestions for a revision of the diagnosis within a categorical or dimensional nosology of psychotic and affective disorders.