The purpose of this study was to evaluate the relationship between a history of childhood physical abuse and later substance abuse, controlling for family history of substance abuse. The study was a cross-sectional survey. Subjects were a convenience sample of mothers with children younger than 6 years being seen for routine care in five pediatric clinics. Mothers were given an anonymous, self-administered questionnaire on demographics, substance abuse, history of physical abuse, and family history of substance abuse. Of the 733 respondents, 24% reported having been physically abused, 24% reported a family history of substance abuse, and 36% had a positive screen for substance abuse. A positive screen for substance abuse was more common among those who reported having been abused than those who had not (47% vs 32%, p <.001). After controlling for family history of substance abuse, a history of being abused remained significantly associated with current substance abuse (odds ratio = 1.58, 95% confidence interval 1.1,2.2). Suffering abuse during childhood is a significant risk factor for later substance abuse, even after controlling for a family history of substance abuse. Clinicians treating victims of abuse may wish to include substance abuse prevention measures.