In populations with non-HIV immunodeficiency, non-Hodgkin lymphoma and soft tissue sarcoma, especially Kaposi's sarcoma, are the most prominent tumours, but Hodgkin's disease, gastric carcinoma, squamous cell skin cancer, malignant melanoma, hepatoma, myeloid leukaemia and/or colorectal carcinoma have been linked in various studies. Population based cancer registries and cohort studies of HIV infected persons have generally failed to detect HIV related increases in total cancer incidence or in specific tumours other than non-Hodgkin lymphoma and Kaposi's sarcoma; however, associations with anal carcinoma, hepatoma and Hodgkin's disease have been suggested by some studies. Although not indicating increased risk, HIV induced immunosuppression has been linked to an acceleration of cervical and anal neoplasia and to increased aggressiveness of Hodgkin's disease with a relative excess of the mixed cellularity type. Advances in treatment for HIV infection will delay progression to AIDS and may allow an altered natural history to emerge, including the occurrence of excesses of additional cancer types.