Objective: The aim of the study was to assess the prevalence of depression in postpartum women as compared with non- postpartum women, and to identify risk factors of depression in both groups. Method: A population based questionnaire study was performed among women 18 40 years in two municipalities in Norway in 1998 1999. A total of 2730 women were included, of whom 416 were in the postpartum period. Results: The prevalence of depression was higher in non- postpartum as compared with postpartum women. High scores on the life event scale, a history of depression and a poor relationship to the partner were associated with depression in both postpartum and nonpostpartum women. When controlling for the identified risk factors of depression the odds- ratio for depression in the postpartum period was 1.6 ( 95% CI: 1. 0 - 2. 6). Conclusion: The risk for depression was increased in the postpartum period, when controlling for the uneven distribution of risk factors.