The first case of Chagasic Miocardiopathy with complete immunologic confirmation is described. 2. The clinical, radiological, and electrocardiographic basis of the case were analyzed. 3. The specificity and the sensibility to the different seroimmunologic reactions in the Chagasic Disease was discussed. 4. An emphasis is placed on the fact that Chagas illness is not a rare entity in the Mexican Republic. 5. We recommend that a campaign of serologic investigation is begin to discover the true frequency of this illness.