Fifty-eight psychoses beginning within two weeks of childbirth are compared with 52 episodes of nonpuerperal psychotic illness occurring in young women. A clinical approach based on the use of multiple information sources and integrated assessment was used. Statistically significant differences between the two groups of patients were found in 52 of 214 psychopathological variables. Postpartum patients had more manic symptoms and "confusion," while nonpuerperal patients had more schizophrenic symptoms. The Research Diagnostic Criteria (RDC) showed an excess of schizoaffective (manic) puerperal patients and schizoaffective (depressed) or schizophrenic nonpuerperal patients. Only five of 58 puerperal episodes met RDC for schizophrenia. The relative lack of schizophrenic symptoms in the puerperal group was confirmed by self-ratings. The results are interpreted as supporting a link between puerperal psychosis and manic-depressive disease.