Research into the biology of human immunodeficiency virus (HIV), and the immunopathogenesis of HIV disease, is proceeding rapidly. New therapies are being developed based on this new knowledge. Meanwhile, the proportion of women in the United States with AIDS is rising, and heterosexual spread is the fastest rising mode of transmission. Overall survival with HIV and AIDS appears to be similar in women and men receiving similar treatment. However, the results of several population-based studies indicate that women are less likely to have received antiretroviral therapy than have men. Gynecologic complications of HIV, including recurrent and refractory vaginal candidiasis and an increased frequency of cervical dysplasia and carcinoma, have only recently been recognized. There are still little data on the effect of pregnancy on the course of HIV disease in women. The implications of current knowledge for prevention and treatment of HIV in women are discussed.