Demographic, obstetric, clinical features and clinical outcome of 100 consecutive admissions to a psychiatric mother and baby unit are presented. Referral patterns by health services involved are also examined. 56% of admissions occurred within 2 weeks of delivery and the mean duration of admission was 2 months. Patients were categorized as having schizophrenia (n = 20), affective psychosis (n = 56) or non-psychotic disorders (n = 24) and these three groups were compared. There were few demographic and obstetric differences between diagnostic categories. The affective psychosis group were more likely to have acute illnesses with an onset and admission occurring within 2 weeks of delivery. Women with non-psychotic disorders were also most likely to become ill within 2 weeks of delivery but tended to be admitted later. Only 7% of the affective psychotic and non-psychotic women were discharged separated from their infants. Women with schizophrenia were less likely to have acute admissions and required greater input of nursing and service resources than mothers with other illnesses but 50% were discharged without their infants. More research is needed into matching models of care to the needs of mothers with different kinds of chronic, recurrent and new episodes of mental illness that present after childbirth. There are few guidelines to aid clinical staff in assessing the risk, current or future, of significant harm to an infant as a consequence of maternal mental illness, particularly of schizophrenia.