Depression may interfere with fathers' ability to effectively fulfill parenting roles, but little is known about the mental health of fathers with newborns. This study examines the prevalence and determinants of depression among fathers with newborns. The results show that married fathers have the lowest rate of depression (6.6 percent), followed by cohabiting (8.7 percent), romantically involved (11.9 percent), and not involved (19.9 percent) fathers. The quality of the relationship with the mother and fathers' substance use problems are important predictors of fathers' depression. Mental health and welfare policy implications are discussed.