Cryptococcal meningitis is a frequently observed opportunistic infection in AIDS patients in Zaire and other countries in Central Africa. The prognosis in those patients is very poor because of the advanced stage of their cryptococcal disease at presentation. To improve the prognosis of cryptococcal meningitis in HIV-infected patients through earlier diagnosis, a routine serum cryptococcal antigen screening was performed on 450 HIV-positive/AIDS patients seen at the Cliniques Universitaires de Kinshasa between 1 January 1988 and 31 August 1988. Cryptococcal antigen was detected in the sera of 55 (12.2%) of them. Cerebrospinal fluid was obtained from 44 of these 55 patients and the presence of Cryptococcus neoformans was demonstrated by direct microscopy and culture in 29 (66%) of them.