The association of malignancies, such as non-Hodgkin's lymphoma and Kaposi's sarcoma, with human immunodeficiency virus infection has been recognized since the beginning of the epidemic. However, an increasing number of tumors not diagnostic of acquired immunodeficiency syndrome has been described in this setting. Taking into consideration that survival of patients with human immunodeficiency virus infection is increasing because of improvement of supportive care and better control of human immunodeficiency virus and related opportunistic infections, oncogenic viruses such as human papillomavirus, hepatitis B virus, Epstein-Barr virus, in a setting of prolonged immunosuppression could increase the risk of a variety of malignant tumors.