This study was designed to identify predictors of relationship outcomes among 179 young (ages 14-24) coparenting couples during the transition to parenthood, with a particular focus on interpersonal process and psychopathology. Findings indicated that couples identified as hostile during the prenatal assessment were more likely to report relationship violence at follow-up (2 years postbirth). Couples identified as warm were more likely to remain together as coparents even if their romantic relationship dissolved. Couples in which the female partner was highly controlling were less likely to be cohabiting at follow-up. Mothers with a history of substance abuse and fathers with a history of conduct disorder were also more likely to engage in interpartner violence. Latino couples were more likely than Caucasian and African American couples to be warmly engaged and to remain romantically involved across the transition to parenthood. (Contains 5 tables and 1 footnote.)