In order to clarify the sequelae of 11 patients who suffered from acute myocarditis of viral origin and were diagnosed by endomyocardial biopsy in the early and the convalescent stage of the disease, left ventriculograms were obtained from 17 to 167 (46.5 +/- 41.2, mean +/- SD) days after the onset of the disease were analyzed. The data were compared with the biopsy findings in the convalescent stage. The mean left ventricular ejection fraction (LVEF) was 57.5 +/- 10.8% and in 3 cases the LVEF was less than 50%. In 2 cases, apparent asyneresis was observed. In all cases coronary arteriographic findings did not show significant stenosis. It is concluded that after viral myocarditis, increase in left ventricular end-diastolic volume, depressed ejection fraction and asyneresis occur in some cases and it can be said that a development from myocarditis to dilated cardiomyopathy occurs.