Certain human genital papillomaviruses (HPV) are strongly associated with cervical dysplasia and cancer. Evidence is accumulating that HPV infection and ano-genital cancers are more common in patients with the acquired immunodeficiency syndrome. The objective of our study was to evaluate the extent to which HPV infection and associated cervical disease constitute opportunistic complications of human immunodeficiency virus (HIV) infection in a population of sexually promiscuous, HIV-infected women in Kinshasa, Zaire. In 1989 we obtained Pap smears and cervicovaginal lavage specimens for HPV DNA testing from 47 HIV-seropositive and 48 HIV-seronegative prostitutes who were part of a cohort under observation since 1988. Thirty-eight percent of the HIV-seropositive and 8% of the seronegative women (odds ratio = 6.8; p = 0.001) had HPV DNA detected by either ViraType, a dot-blot assay which detects specific genital HPV types, or low-stringency Southern blot, which detects all HPV types. Eighty-two women (86%) had an interpretable Pap smear; 11 of 41 (27%) HIV-seropositive women and one of 41 (3%) seronegative women had cervical intra-epithelial neoplasia (CIN) (odds ratio = 14.7; p = 0.002). HIV seropositivity, HPV infection and CIN were highly associated. Eight (73%) of 11 seropositive women with CIN had HPV detected. Both HPV infection and cervical cancer may emerge as opportunistic complications of HIV infection in populations in which HIV, HPV and cervical cancer are common.