To determine the effect of HIV-1 and HIV-2 infection on the prevalence of cervical human papillomavirus (HPV) and squamous intraepithelial lesions (SIL) in a population of high-risk women in Senegal. Cross-sectional study among 759 female commercial sex workers, including 68 with HIV-1, 58 with HIV-2, 14 with HIV-1 and 2, and 619 without HIV infection. Overall, HPV was detected in 43% of women by polymerase chain reaction (PCR), and in 7% by Southern transfer hybridization, with 7.4% of all women having SIL. The mean CD4 count was 820, 1205, and 727 x 10(6)/l for those with HIV-1, HIV-2, and dual HIV-1 and 2 infections, respectively, and 1447 x 10(6)/l for those without HIV infection. Both HIV-1 and HIV-2 were associated with HPV, as detected by PCR [HIV-1 odds ratio (OR), 2.9; 95% confidence interval (Cl), 1.7-4.9; HIV-2 OR, 1.7; 95% Cl, 1.0-2.9]. HIV-2 was also associated with cervical SIL, and although the association between HIV-1 and SIL did not attain statistical significance, a trend was apparent (HIV-1 OR, 1.8; 95% Cl, 0.7-4.7; HIV-2 OR, 2.9; 95% Cl, 1.2-7.2). Despite less immunosuppression with HIV-2, both HIV-1 and HIV-2 were associated with detection of HPV. HIV-2 was also associated with SIL. Further studies are needed to examine the risks of high-grade SIL and invasive cervical cancer with HIV-1 versus HIV-2 infection.