Human immunodeficiency virus (HIV) and human papillomavirus (HPV) are both sexually transmitted viruses with many risk factors in common. Studies have found that HIV-seropositive women are at least five times as likely to be infected with HPV as seronegative controls. In immunocompromised HIV-seropositive women, the risk of cervical intraepithelial neoplasia (CIN) is almost as high as in women with squamous intraepithelial lesions on their Pap smear. Some studies have shown the false-negative rate of cervical cytology in HIV-seropositive women to be very high, although others have shown it to be comparable with the rate in seronegative controls. However, given the prevalence of CIN in this population, even a "normal" false-negative rate may result in many missed CIN lesions. Among HIV-seropositive women and especially among those who are immunocompromised, CIN is more likely to progress and recur after treatment. Recurrence rates may reach 87 percent 36 months after treatment in markedly immunosuppressed women. Cryotherapy is especially ineffective in these patients. Vulvar condyloma and vulvar intraepithelial neoplasia (VIN) are much more prevalent in HIV-seropositive women and especially in those who are markedly immunosuppressed or who have been immunosuppressed for a prolonged period of time. It is recommended that all HIV-seropositive women undergo periodic evaluation at intervals no less than every 6 months. Immunocompromised women should be followed with cytology and colposcopy of the cervix and vulva, although those with normal immune systems may be followed with cytology alone. Because the rates of recurrence and progression are so high after treatment of these women, they should be followed with colposcopy and cytology every 6 months. New approaches to treatment need to be explored in this population. BACKGROUND Obstetricians & Gynecologists, Family Physicians. OBJECTIVE After completion of this article, the reader will understand the association between the immune suppression of HIV and HPV-related diseases, be familiar with the treatment options for the HIV-seropositive woman with cervical intraepithelial neoplasia (CIN), understand the natural history of CIN in the patient with HIV-seropositivity, and become aware of the appropriate surveillance of the HIV-seropositive woman treated for CIN.