The French version of the Marc?hecklist was used to collect data for 176 joint admissions to 11 psychiatric mother-baby units in 1999 and 2000. Mean age of the babies at admission ranged from 4 to 16 weeks. Two units also admitted older children. Mothers admitted were diagnosed with schizophrenia or chronic delusional disorders (n = 44), acute transitory psychosis "Bouff?d?rante" (n = 20), bipolar disorders (n = 20), depressive illness (n = 38), personality disorders or intellectual disability (n = 39), and other disorders (n = 15). The mean duration of hospitalisation was 11 weeks. Units that also offered day-care admission in the same or a near-by unit had shorter mean admissions. More than half the women's partners (or babies' fathers) had mental health problems. Women with schizophrenia or chronic delusional disorders and personality disorders or intellectual disability remained hospitalised longer, improved less, and were more often separated from their babies, or discharged with supervision, than women admitted with other diagnoses.