This study examined the prevalence of and risk factors for intimate partner physical violence against women. Interviews were conducted with a sample of 1,378 men working in Cape Town municipalities. An average of 42.3% (95% CI: 39.6, 44.8) reported physical violence against a partner of the last 10 years, and 8.8% (95% CI: 7.3, 10.3) reported physical violence in the past year. After adjustment for age, occupational group, and race, the factors associated with use of violence against partners of the last 10 years were having no post-school training (OR = 2.10), witnessing parental violence in childhood (OR = 1.87), involvement in fights at work (OR = 2.73) and in communities (OR = 1.54), drug use (OR = 1.99), problem alcohol use (OR = 1.98), perceiving hitting women to be acceptable (OR = 4.54), frequent conflict (OR = 2.40), women's alcohol use (OR = 2.25), conflict about sex (OR = 2.16), and conflict about his infidelity (OR = 2.81). The study shows that ideas supportive of gender inequality and normative use of violence in different settings are major underlying factors for men's violence against partners.