Since the advent of HAART, the natural history of HIV disease has been changing, with decreased risk of life-threatening opportunistic infections and prolonged survival. Concurrently, a variety of non-AIDS-defining cancers have been reported with increased incidence in HIV-infected adults, including anal cancer, Hodgkin's disease, head and neck cancer, testicular cancer, lung cancer, colon cancer, basal cell cancer, squamous cell cancer of the skin, and melanoma. It appears that these tumors may have a more aggressive clinical course in HIV-infected people. Available data, however, suggest that antitumor response and survival in HIV-infected people with malignancy are improved in people with higher CD4 counts. The possible mechanisms for the increased incidence and altered clinical course of these malignancies in HIV-infected people remain unclear.