In a group of 82 children followed up for prolonged periods the authors draw attention to some problems of virus myocarditis. They focused attention on the diagnosis of Coxsackie myocarditis for which they elaborated a scoring system. Based on this system they separated the prognostically most adverse group where cardiac decompensation was the dominant sign from the very beginning. They confirmed the theoretical assumption that in some children virus myocarditis develops into cardiomyopathy. This was proved in six children by histological examination and in 19 children by means of echocardiography.