HIV infection predisposes to the development of non-Hodgkin lymphoma (NHL). The frequency of NHL among HIV-positive adults and children in sub-Saharan Africa is not known. In 1991-1992, a representative autopsy study of HIV infection was performed in Abidjan, Côte d'Ivoire. Of 247 HIV-positive adult (> 14 years) medical patients dying in hospital, 2.8% had NHL, 1.6% with visceral NHL and 1.2% with primary cerebral lymphoma. The estimated crude incidence of NHL among HIV-positive adults in Abidjan was 84/100,000 per year, 10-fold greater than the expected pre-AIDS incidence of NHL but less than the incidence observed among HIV-positive adults in industrialised countries. None of 78 autopsied HIV-positive children (median age = 17 months) had NHL. HIV infection augments the incidence of NHL among adults in Africa, but short survival with advanced HIV disease probably prevents the major increase in HIV-associated NHL seen in industrialised countries. Survival of HIV-positive children in Africa appears too short to permit the significant development of additional NHL; classic Burkitt lymphoma is not an AIDS-associated tumour in Africa.