Eighty six in-patients suffering from puerperal psychosis within six weeks after childbirth were prospectively investigated in Muhimbili National Hospital during two years. Formal psychiatric history, mental status evaluation, research and diagnostic criteria including ICD 10 and clinical progression were employed for diagnosis. Using a structured questionnaire, the socio-demographic characteristics, concomitant physical disorders, major obstetric events, period of onset of puerperal psychosis following delivery and social support given were established. Mean age was found to be 23.6 years; the majority was primiparous women with parity of between one and three children. Main physical co-morbidities included anaemia in 51.4% of cases, infections in 44.2% and EPH-gestosis in 17.4%. Most mothers received social support from their extended families. Organic psychosis was found in four fifths of the mothers and schizophrenia in 8.1%. A high rate of early onset puerperal psychosis (3.2/1000 (births), predominantly in young primiparous women, was found.