We conducted a cross-sectional study with 385 HIV-positive women in Bangkok to assess the prevalence and predictors of cervical abnormalities on Papanicolaou (Pap) smear. Low-grade squamous intraepithelial lesions (LSIL), high-grade SIL (HSIL) and invasive cervical cell cancer (ICC) were assessed by cytological examination after Pap smear and logistic regression models were used to assess associations with patient characteristics. Overall prevalence of LSIL, HSIL and ICC were 11.2% (95% confidence interval [CI] 8.2-14.7%), 4.7% (95%CI 2.8-7.3%) and 0.5% (95%CI 0.06-1.9%), respectively. In multivariate models, only the nadir CD4 count and income remained significantly associated with cytological abnormalities, whereas smoking, hormonal contraceptive or antiretroviral use, condom use, parity and number of lifetime sexual partners were not associated. The odds ratio for having cytological abnormalities was 2.6 (95% CI 1.24-5.34) in those with a nadir CD4 count <200 cells/mm3 compared with those with a higher nadir CD4 count, and 1.99 (1.11-3.57) in those with an income of <125 US dollars/month compared with those with higher incomes. In settings where access to affordable treatment is improving, this study reinforces the importance of regular Pap smear screening in HIV-positive women, particularly those with low nadir CD4 counts and lower incomes.