A number of immunodeficiency states--both inherited (such as agammaglobulinaemia, Bloom's syndrome, hereditary telangiectasia) and acquired (e.g. immunosuppressive therapy) have been associated with varieties of cancers. HIV induces more profound immunodeficiency state and it should not be difficult to imaging why cancer diagnosis is made in over 40% of HIV infected patients. Impairment of normal function of natural killer cells as a result of lack of helper signals from CD4+ T-lymphocytes may be a major mechanism of increased susceptibility to cancer development in HIV infected patients. Although many neoplastic diseases could occur at a frequency not higher than would be expected by chance alone, the biological behaviour of such malignancies tend to be more aggressive. Three neoplastic diseases are associated so commonly with HIV infection that each of them has become recognized as an AIDS defining illness. These are Kaposi's Sarcoma (KS), Non-Hodgkin's Lymphoma (NHL) and Cervical Carcinoma. Both KS and NHL were recognized as AIDS associated cancers from the onset of the epidemic in 1981 but carcinoma of the cervix became AIDS defining in 1993. The epidemiology, aetiopathogenesis, clinical manifestation, diagnostic tools and modalities of therapeutic intervention for KS and NHL form the subject of this review.