Over a period of 23 months, 30 cases of cryptococcosis have been studied in Bujumbura (Burundi). Through them, epidemiological and clinical aspects have been underlined, and attempts have been made to establish links between cryptococcosis and A.I.D.S., which is significantly frequent in Central Africa. Cryptococcosis strikes young adults (40% between 30 and 35 years of age). Its high frequency in Bujumbura among patients infested by A.I.D.S., suggest some thoughts. A.I.D.S. in Central Africa, and particularly in Burundi, presents some peculiarities linked to surrounding and possibilities of diagnosis: opportunistic diseases are of different frequency in temperate or tropical climates: pneumocystosis are more frequent in U.S.A. but cryptococcosis and candidosis are more frequent in Africa because their diagnosis is easier. lack of classical risk factors in African populations is known, but other risk factors have to be taken into consideration: tuberculosis, intestinal parasitosis, chronic virus B hepatitis, protein-caloric deficiency.