A community cohort of 206 European and Maori women completed a questionnaire screening for postnatal depression at 4 weeks postpartum. The prevalence of major depressive disorder amongst the women was 7.8% with a further 13.6% of women experiencing more minor depressive symptoms. Postnatal depression was more likely to occur in women who were single, were less than 20 years old at the birth of their first child, were unhappy with their relationship with their partner, had a history of previous psychiatric hospitalisation, and were Maori. Women who were depressed were more likely to show a lack of enjoyment of and less positive attitude towards their infant. The study highlights the value of screening for postnatal depression with a simple questionnaire, as few depressed women would have been otherwise recognised.