ABSTRACTLimited research exists on the impact of prison mother and baby unit (MBU) residence. Research in the UK suggests women in MBUs have lower prevalence of mental disorder. Higher rates of mother-child attachment for women in prison nurseries in the US have been reported. Eighty-five pregnant women were interviewed at baseline and 62 followed up in nine different prisons. The Edinburgh Postnatal Depression Scale (EPDS) was used to measure perinatal depression; the World Health Organisation Quality of Life (WHOQOL – BREF), for quality of life; and the Mother-to-Infant Bonding Scale (MIBS) for mother-child bonding. EPDS scores were higher at baseline than follow-up. Women admitted to MBUs had lower EPDS scores at baseline and follow-up, and this reduction was greater than for women not admitted to MBUs. WHO-QOL scores were higher at follow-up than baseline on all domains, except the social domain for those not admitted to MBUs. Findings suggest women with perinatal depression are less likely to be admitted to MBUs, and MBU placement may contribute to a reduction in perinatal depression. Increased QOL-BREF scores at follow-up suggest improved quality of life for all participants. Reduced support post-separation may contribute to lower social domain scores for women not admitted to MBUs.