Violence between romantic partners is widespread, but developmental precursors of perpetration and victimization are little understood. Among participants followed from birth to 23 years of age, familial and extrafamilial childhood and adolescent relationships were examined in connection with couple violence in early adulthood. Predictors included early childhood physical abuse and witnessing of parental partner violence, features of parent-child interactions at the age of 13 years, and close friendship quality at the age of 16 years. Controlling for early familial violence, intrusive or overly familiar behavior in videotaped parent-child collaborations at 13 years of age consistently predicted violence perpetration and victimization in early adulthood. Friendship quality at the age of 16 years contributed over and above familial predictors. Understanding the role of both familial and extrafamilial close relationship precursors may lead to effective strategies for ameliorating the problem of romantic partner violence.