In this study prevalence of cervical intraepithelial neoplasia (CIN) and genital condylomatosis in HIV-positive women and the possible relation between HIV and HPV infection and CIN have been analyzed. 66 seropositive women underwent cytological, colposcopic and, when necessary, histologic examination and the results have been compared with those obtained from 150 HIV-seronegative controls. HIV-positive patients were divided in two groups, depending on number of CD4+/mm3, < 400 or > = 400, to evaluate the relation between immunity and HPV infection and/or CIN. 35 seropositive and 136 seronegative patients affected by genital condylomatosis and/or CIN I were submitted to laser CO2 vaporization and the results of the treatment have been compared. All cases of CIN II and III underwent laser CO2 conization. Among HIV-seropositive patients the prevalence of genital condylomatosis appeared to be 87.9% and among the seronegative controls 18% (p < 0.001). Multilocated condylomatosis represented 58.7% of genital condylomatosis among seropositive women and 11.1% among the seronegative patients. In HIV-seropositive group the prevalence of genital condylomatosis was of 95.2% among women with CD4+ < 400 and of 75% among those with CD4+ > = 400 (p > 0.01). 13 patients (19.7%) of the 66 seropositive women and 12 of the 150 (8%) seronegative had a cervical intraepithelial neoplasia. A CIN III was diagnosed in 9 seropositive patients (13.6%) and in 5 seronegative (3.3%). Among the HIV-seropositive women who underwent laser vaporization for genital condylomatosis a cure-rate of 34.5% was found; among seronegative women who underwent the same treatment the cure-rate was of 79.4%. Those patients who underwent laser conization resulted all cured at first check. In the group of HIV-seropositive women a higher prevalence (p < 0.001) of genital condylomatosis, particularly multilocated localization, has been found than in HIV-seronegative patients. An increased prevalence of CIN has also been found among HIV-seropositive women. Genital condylomatosis in seropositive patients resulted extremely difficult to treat with laser vaporization in contrast with the 100% success in laser conization for high-grade CIN.