This longitudinal study was designed to provide data on sex differences in the course of schizophrenia and other psychotic disorders. Ninety-seven participants (43 women and 54 men) were assessed during index hospitalization when they were in the acute phase of illness and then reassessed prospectively at 6 consecutive follow-ups over a 20-year period. Patients were evaluated by a series of standardized measures on many aspects of illness including the presence of psychosis, global outcome, and rate of recovery. When women were compared to men in this sample, the data demonstrated a lower percentage of psychotic activity for women over the course of illness (significant at the 7.5- and 20-year follow-ups), and a significant improvement in psychotic activity over 20 years for women (P < .05), but not for men. In addition, women showed significantly better global functioning (P < .05) at 3 of the 6 follow-ups (the 2-, 7.5-, and 10-year follow-ups). Significantly higher percentages (P < .05) of women were in recovery at 2 of the 6 follow-up years (the 2- and 10-year follow-ups). Cumulatively, 61% of the women with schizophrenia showed a period of recovery at some point during the 20-year period compared to 41% of the men. The sex difference patterns were similar for patients with schizophrenia and for those with other types of psychotic disorders. Sex differences in this sample were specifically not attributable to differences in age of onset or premorbid developmental achievements.