Background The aim of the study was to identify risk factors for depression and to estimate its prevalence in postnatal mothers. Methods This cross-sectional and multi-centre study was carried out on 1,350 Turkish women in their first postnatal year. Measures included a structured questionnaire and the Turkish version of the Edinburgh Postnatal Depression Scale (EPDS). Results Of the women, 31.1% had a score of 13 or higher on the EPDS. The mean score and standard deviation was 9.8 +/- 5.7. In the multivariate analysis, EPDS scores were significantly associated with economic status, access to support from family members and close friends, emotional distress at the pregnancy, whether the pregnancy was planned, health problems during pregnancy, the perceived standard of baby care after delivery, and mental disorder before and during pregnancy. Conclusion The prevalence of EPDS-based depression among Turkish women in postnatal the period was high, and was associated with several social, economic and demographical factors.