OBJECTIVE: To identify factors associated with prevalent HIV in a national HIV survey in Kenya. METHODS: The Kenya AIDS Indicator Survey was a nationally representative population-based sero-survey that examined demographic and behavioral factors and serologic testing for HIV, HSV-2 and syphilis in adults aged 15-64 years. We analyzed questionnaire and blood testing data to identify significant correlates of HIV infection among sexually active adults. RESULTS: Of 10,957 eligible women and 8,883 men, we interviewed 10,239 (93%) women and 7,731 (87%) men. We collected blood specimens from 9,049 women and 6,804 men of which 6,447 women and 5,112 men were sexually active during the 12 months prior to the survey. HIV prevalence among sexually active adults was 7.4%. Factors independently associated with HIV among women were region (Nyanza vs Nairobi: adjusted OR [AOR] 1.6, 95%CI 1.1-2.3), number of lifetime sex partners (6-9 vs 0-1 partners: AOR 3.0, 95%CI 1.6-5.9), HSV-2 (AOR 6.5, 95%CI 4.9-8.8), marital status (widowed vs never married: AOR 2.7, 95%CI 1.5-4.8) and consistent condom use with last sex partner (AOR 2.3, 95%CI 1.6-3.4). Among men, correlates of HIV infection were 30-to-39-year-old age group (AOR 5.2, 95%CI 2.6-10.5), number of lifetime sex partners (10+ vs 0-1 partners, AOR 3.5, 95%CI 1.4-9.0), HSV-2 (AOR 4.7, 95%CI 3.2-6.8), syphilis (AOR 2.4, 95%CI 1.4-4.0), consistent condom use with last sex partner (AOR 2.1, 95% CI 1.5-3.1) and lack of circumcision (AOR 4.0, 95%CI 2.8 - 5.5). CONCLUSION: Kenya's heterogeneous epidemic will require regional and gender-specific prevention approaches.