Survival with HIV infection is shorter in sub-Saharan Africa than in developed countries. The pattern of HIV transmission in our region has changed from homosexual to heterosexual, with viral subtypes similar to those in North America/Europe and Central Africa, respectively. We compared survival for the two transmission patterns after AIDS, and after the first CD4+ lymphocyte counts < 200/microliter and < 50/microliter, for adults presenting 1988-1993. Antiretroviral therapy was excluded. There were 180 homosexuals (63% White, 56% employed) and 314 heterosexuals (67% Black, 34% employed). Extrapulmonary tuberculosis was the AIDS-defining diagnosis in 36/90 heterosexuals and 5/58 homosexuals (p < 0.0001). Survival after AIDS was longer in heterosexuals (p = 0.0015), but AIDS occurred earlier as shown by their higher CD4+ count at AIDS onset (median 98/microliter vs. 40/microliter; p = 0.036). Survival was similar in the two groups after first CD4+ count < 200/microliter and < 50/microliter. Race, socioeconomic status and morbidity are markedly different in the two transmission groups. AIDS occurs with less severe immune suppression in heterosexuals, with correspondingly longer survival. Survival after defined CD4+ counts, however, is remarkably similar.