The AIDS epidemic continues unabated in Africa, Asia, and South America, and since patients survive longer, the number of chronically immunocompromised individuals is increasing in Europe and the United States. The number of children with HIV infection who will ultimately develop a malignancy is not known. Currently, tumors represent about 2% of the AIDS-defining events in children in the United States, but the incidence might be different in developing countries. The most common tumors in HIV-infected children are non-Hodgkin's lymphoma, smooth muscle tumors (leiomyosarcomas), and Kaposi's sarcoma (only in Africa). This article provides an overview of epidemiology and clinical and pathological presentations, as well as preliminary data regarding treatment options in children with HIV-associated malignancies.