The relationship between sexually transmitted diseases (STDs) and risk for human immunodeficiency virus (HIV) has been established. Little is known, however, about the relationship between being infected with an STD and initiating HIV risk-reduction behavior. We interviewed 267 young women who were family planning clients of the San Francisco Bay-Area Planned Parenthood clinics, of whom 40% were white, 37% African American, and 23% women of other ethnic origins. Fifty-three percent of the women surveyed reported having been diagnosed with an STD, and 22% reported two or more episodes of infection. African-American women who reported lower educational attainment and being unemployed were more likely to report having been infected with an STD than were women from other ethnic and demographic groups. Ethnic differences were also found in the prevalence of the risk behaviors associated with the self-reported STDs and in the relationship between reporting a history of STD and practicing HIV risk-reduction behavior. Women who reported an STD were significantly more likely to report having a nonmonogamous primary partner. Risk-reduction behaviors associated with a personal history of STD included being less likely to report having asked a sexual partner about his number of previous partners and being more likely to have been tested for antibodies to HIV. Results from this survey suggest that these family planning clients report a frequent history of STDs and that while some have attempted to reduce their risk, these efforts are inadequate. These data underscore a need for ethnically relevant HIV risk-reduction interventions for this population.