The paper presented the results obtained in studying the patients with acute rheumatic fever for antibodies to cardiolipin (ACL). The study resulted in the establishment that the development of immunopathies in the presence of acute rheumatic fever combined with the acute streptococcal infection was accompanied by hyperproduction of ACL (more common IgG versus IgM isotypes). The phenomenon mentioned widened the spectrum of acute infectious diseases associated with an increase in ACL synthesis. It was also stated that increased ACL contents were closely related with the involvement of the cardiac valves. Authentic clinical and echocardiological signs of the heart disease were mainly revealed in the patients with high contents of IgG and IgM isotypes of ACL. A certain relationship between the laboratory activity of the disease and ACL hyperproduction was noted as well. The latter permitted the discussion on the impact of streptococcal infection initiating the development of acute inflammation on the hyperproduction of ACL.