OBJECTIVE: We describe the prevalence of depressive and bipolar spectrum episodes in fathers in antenatal and postnatal periods, as well as at 12 months after childbirth. METHOD: A longitudinal follow-up study was conducted with a representative sample of 739 fathers whose children were born between April 2007 and May 2008 in maternity wards in the city of Pelotas, southern Brazil. Paternal psychopathology was measured with the Mini Neuropsychiatric Interview (MINI) across three time points: between 28 and 34 weeks of pregnancy (T1), 30 to 60 days postpartum (T2), and 12 months after childbirth (T3). RESULTS: The prevalence of depressive episodes was 5.0% at T1, 4.5% at T2, and 4.3% at T3. Mixed episodes were present in 3%, 1.7%, and 0.9% of subjects, respectively, and accounted for 61.1% of the cases of depression in the antenatal period, 37.5% in postpartum, and 21.4% at 12 months. Depressive and manic/hypomanic episodes were significantly associated during pregnancy and in postpartum, but not at 12 months after childbirth. CONCLUSION: Bipolar episodes were common in men with depressive symptoms during their partner's pregnancy in the postpartum period and, to a lesser extent, 12 months after childbirth. Therefore, this population should be carefully investigated for manic and hypomanic symptoms.