Despite a high prevalence of intimate partner violence in South Africa, few epidemiological studies have assessed individual risk factors and differential vulnerability by gender. This study seeks to analyze gender differences in risk for intimate partner violence victimization and perpetration according to childhood and adult risk factors in a national sample of South African men and women. Using data from the cross-sectional, nationally representative South Africa Stress and Health Study, the authors examine data from 1,715 currently married or cohabiting adults on reporting of intimate partner violence. Our analysis include (a) demographic factors, (b) early life risk factors (including exposure to childhood physical abuse, witnessing parental violence, parental closeness, and early onset "DSM-IV" disorders), and (c) adult risk factors (including experiencing the death of a child and episodes of "DSM-IV" disorders after age 20). Although prevalence rates of intimate partner violence are high among both genders, women are significantly more likely than men to report being victimized (29.3% vs. 20.9%). Rates of perpetrating violence are similar for women and men (25.2% and 26.5%, respectively). Men are more likely to report predictive factors for perpetration, whereas women are more likely to report predictors for victimization. Common risk factors among men and women reporting perpetration include exposure to childhood physical abuse, witnessing parental violence, and adult onset alcohol abuse/dependence. However, risk factors in male perpetrators are more likely to include cohabitation, low income, and early and adult-onset mood disorders, whereas risk factors in female perpetrators include low educational attainment and early onset alcohol abuse/dependence. The single common risk factor for male and female victims of partner violence is witnessing parental violence. Additional risk factors for male victims are low income and lack of closeness to a primary female caregiver, whereas additional risk factors for female victims are low educational attainment, childhood physical abuse, and adult onset alcohol abuse/dependence and intermittent explosive disorder. Intimate partner violence is a significant public health issue in South Africa, strongly linked to intergenerational cycling of violence and risk exposure across the life course. These findings indicate that gender differences in risk and common predictive factors, such as alcohol abuse and exposure to childhood violence, should inform the design of future violence-prevention programs and policies. (Contains 4 tables.)