A 20 per cent prevalence of mild clinical depression was found in 120 women assessed at about six weeks postpartum. The strongest associated factor was occurrence of recent stressful life events. Previous history of psychiatric disorder, younger age, early postpartum blues, and a group of variables reflecting poor marital relationship and absence of social support were also notable. Poor marital support acted as a vulnerability factor, only producing an effect in presence of stressful life events. Previous psychiatric history produced a strong independent effect, both with and without life events. Postpartum blues were only associated with depression in the absence of life events, suggesting a small hormonal sub-group. Overall the findings indicate the importance of social stress in puerperal depression.