The International Symposium on Immunologically Mediated Heart Disease highlighted a number of controversial issues about the etiology and pathogenesis of myocarditis and dilated cardiomyopathy. They include the role of virus infection in initiating the disease, genetic regulation in the host, the interplay between virus persistence and autoimmunity in producing the later phases of disease, the antigenic determinants responsible for inducing autoimmune disease, and the pathogenetic effector mechanisms. Most of these questions can best be explored by detailed analysis of animal models followed by careful correlation with clinical, epidemiological, and pathological studies of human cases of myocarditis and dilated cardiomyopathy. Based on the new insights gained from these studies, future therapies for immunologically mediated heart disease may emerge.