This study described the natural history of depression in mothers who recently gave birth in a low-income country and to investigate the effect of risk factors, particularly related to infant gender bias, on the occurrence and outcome of depression. The authors studied a group of pregnant mothers recruited during their third trimester of pregnancy from a district hospital in Goa, India. The mothers were interviewed at recruitment, 6-8 weeks, and 6 months after childbirth. Interview data included presence of antenatal and postnatal depression, obstetric history, economic and demographic characteristics, and gender-based variables (preference for male infant, presence of marital violence). Depressive disorder was detected in 59 (23%) of the mothers at 6-8 weeks after childbirth; 78% of these patients had had clinically substantial psychological morbidity during the antenatal period. More than one-half of the patients remained ill at 6 months after delivery. Economic deprivation and poor marital relationships were important risk factors for the occurrence and chronicity of depression. The gender of the infant was a determinant of postnatal depression; it modified the effect of other risk factors, such as marital violence and hunger. Depressed mothers were more disabled and were more likely to use health services than nondepressed mothers. Maternal and infant health policies, a priority in low-income countries, must integrate maternal depression as a disorder of public health significance. Interventions should target mothers in the antenatal period and incorporate a strong gender-based component.