The current study examined how antisocial personality disorder (APD) and substance use disorder contributed to partners' reports of physical partner violence among single and dual substance-abusing couples. Participants were 69 heterosexual couples entering treatment in which one or both partners met criteria for substance use disorder. APD diagnosis of the male partner was linked to significantly higher male-to-female and female-to-male perpetration of physical partner violence and victimization. Female partner's APD diagnosis was associated with women's reports of victimization by their male partners. Dual substance use diagnosis emerged as a moderator, in which the effect of men's APD diagnosis on men's perpetration of physical partner violence and victimization was significantly reduced if both partners had substance use disorder. Findings underscore the importance of both partners' APD diagnosis and substance use status for understanding physical partner violence among single and dual substance-abusing couples.