Since first individualized in Atlanta in 1981, the frequency of AIDS is constantly increasing and the risk groups (male homosexuals, heroin addicts, transfused hemophiliacs, Haitians and Africans) are no longer the only ones concerned. The progression of the disease in African heterosexuals foreshadows its probable course in the Western World. 8,000 AIDS cases were indexed in Europe as of June 1987; 45,000 are expected in 1989. Cardiologists are a priori much less concerned by this disease than infectious disease specialists, internists, dermatologists, respiratory diseases specialist or neurologists. However, under three circumstances they may have to become involved in this disease. 1) AIDS following blood transfusions: the greater the risk as the amount of blood transfused is important; patients undergoing ECC present an increased risk. As of June 30 1988, 320 cases of posttransfusion AIDS had been reported in France (7.82 p. cent of all reported AIDS cases). The mean incubation period, estimated at 54 months in 1986, would actually be much longer: distribution according to a Gauss curve with a period of 15 years +/- 5, which would lead to expect many cases in the years to come affecting patients who were transfused before August 1985, when systematic screening became mandatory. Since that time, the risk has markedly decreased but is not non-existent (pre-serology phase, contamination with HIV 2), resulting in a limitation of the indications of transfusions and restoring as often as possible to autotransfusion and normovolemic hemodilution.