The impact of alcohol use on the efficacy of an HIV/STI intervention designed for young African-American women in predicting STIs was examined. Eight hundred forty-eight African-American women, 18–29 years, were randomly assigned to either the HIV/STI intervention or a control condition. Participants were assessed on alcohol use and provided two vaginal swab specimens for STI testing. Women in the intervention who consumed alcohol were less likely to test STI-positive than women in the control and abstainers (AOR = 2.47, 95 % CI = 1.01–6.22). STI risk factors may vary across different populations. Further research on heavy drinking and HIV intervention efficacy is needed.