Women represent almost half of the people living with HIV worldwide. Although social discrimination has been recognized as a major obstacle to HIV prevention, few empirical studies have examined the effects of sexism on women's HIV sexual risk behaviors. We analyzed data collected from an ethnically diverse sample of 754 women attending family planning clinics in the San Francisco Bay Area. A majority of respondents reported lifetime experiences of sexism (e.g., 94% reported sexual harassment). Structural equation modeling results demonstrated that experiences of sexism and reports of recent unprotected sex with a primary or a secondary sexual partner were linked through psychological distress and difficult sexual situations. Our results suggest the need to develop HIV prevention strategies for women that address two mechanisms-psychological distress and difficult sexual situations-that link social discrimination to women's sexual risk for HIV.