A case of a puerperal psychosis in a 26-year-old woman who had a strong family history of schizophrenia is reported. Her symptoms resolved with chlorpromazine and electroconvulsive therapy, but recurred each month just before the onset of menses. The cyclical recurrence of symptoms was prevented by therapy with danazol, a synthetic steroid which inhibits ovulation and may influence several levels of the reproductive control mechanism from the hypothalamus to the uterus. This therapy may be helpful for other women who suffer from recurrence of severe psychiatric disorders in close association with the menstrual cycle.