An unselected sample of 543 children was followed over 20 years to test the independent effects of parenting, exposure to domestic violence between parents (ETDV), maltreatment, adolescent disruptive behavior disorders, and emerging adult substance abuse disorders (SUDs) on the risk of violence to and from an adult partner. Conduct disorder (CD) was the strongest risk for perpetrating partner violence for both sexes, followed by ETDV, and power assertive punishment. The effect of child abuse was attributable to these 3 risks. ETDV conferred the greatest risk of receiving partner violence; CD increased the odds of receiving partner violence but did not mediate this effect. Child physical abuse and CD in adolescence were strong independent risks for injury to a partner. SUD mediated the effect of adolescent CD on injury to a partner but not on injury by a partner. Prevention implications are highlighted.