The prevalence of oral lesions was assessed in a five-center subset of the Women's Interagency HIV Study (WIHS) and correlated with other features of HIV disease. Oral examinations were performed by dental examiners on 729 women (577 HIV-positive and 152 HIV-negative) during baseline examination. Significant differences between the groups were found for the following oral lesions: pseudomembranous candidiasis, 6.1% and 2.0%, respectively; erythematous candidiasis, 6.41% and 0.7%, respectively; all oral candidiasis, pseudomembranous and/or erythematous, 13.7% and 3.3%, respectively. Hairy leukoplakia was observed in 6.1% of HIV-positive women. No significant differences were found for recurrent aphthous ulcers, herpes simplex lesions, or papillomas. Kaposi's sarcoma was seen in 0.5% of HIV-positive and 0% of HIV-negative women. Using multiple logistic regression models controlling for use of antiretrovirals and antifungals, in HIV-positive women the presence of oral candidiasis was associated with a CD4 count <200 cells/microl, cigarette smoking, and heroin/methadone use; the presence of hairy leukoplakia was not related to CD4 count but was associated with high viral load. Oral candidiasis and hairy leukoplakia are confirmed as being common features of HIV infection in women and appear to be associated with HIV viral load, immunosuppression, and various other behaviorally determined variables.