GOALS: We assessed baseline prevalence of human immunodeficiency virus type 1 (HIV-1) and other STDs, as well as behavioral and biologic risk factors for HIV-1 in a population of female bar/hotel workers in Moshi, Tanzania. STUDY DESIGN: Between 2002 and 2003, we enrolled 1042 female bar/hotel workers in an ongoing prospective cohort study. We analyzed data collected at baseline to assess the associations between alcohol, sexual behavior, STDs, and HIV-1 infection. RESULTS: The prevalence of HIV-1 infection was 19.0% (95% confidence interval [CI] = 16.6%-21.4%). Consistent condom use was low (11.1%). HIV-1 was associated with genital ulcers on examination (adjusted odds ratio [AOR] = 2.08, 95% CI = 1.16-3.74), herpes simplex virus type 2 (HSV-2) (AOR = 3.80, 95% CI = 2.42-5.97), and problem drinking (AOR = 1.92, 95% CI = 1.06-3.47). Other independent predictors of HIV-1 were increasing age, number of sex partners, cohabitating, formerly married, location of employment, and having a husband with another wife. CONCLUSIONS: These findings suggest that programs designed to control HSV-2, reduce the number of sexual partners and alcohol use, and promote condom use could be effective in reducing transmission of HIV-1 in this population.