Prospective studies in Africa have demonstrated that vaginal infections are associated with a significant increase in a woman's risk of infection with HIV-1. Further clinical and epidemiological research is needed to evaluate strategies for prevention and treatment of vaginal infections as a means of reducing HIV-1 acquisition. Developing a vaginal health intervention to reduce the risk of HIV-1 infection is a particularly important goal in sub-Saharan Africa, where female controlled strategies for reducing the risk of HIV-1 transmission may be an important means of decreasing the spread of the epidemic. This study will evaluate the efficacy of a regimen for reducing the rate of vaginal infections. The study is a double blind, randomized, controlled trial of monthly treatment with single-dose metronidazole and fluconazole as a means of decreasing vaginal infections and promoting normal vaginal flora in HIV-1 seronegative female sex workers (FSWs) in Mombasa, Kenya. Participants will be recruited from an existing cohort of HIV-1 seronegative FSWs followed at a municipal sexually transmitted disease (STD) clinic in Mombassa, Kenya, since February 1993. Participants will be randomized to treatment with metronidazole 2 grams plus fluconazole 150 mg once a month or placebo. All patients will be asked to return for follow-up after 1 month. All women in the study will be treated as indicated for symptomatic vaginal infections, other genital track infections and followed until they have completed 12 monthly follow-up visits.