The results of serial echocardiographic examination of 51 patients with primary myocardial infarction are discussed. Echocardiography was performed on the 1st, 3rd, 5th, 7th, 10th, and 20th days of the disease and before discharge. Thirty patients had infarct of the anterior wall and 21 of the posterior wall. The dynamics of left ventricular asynergy, end diastolic index, and volume/pressure coefficient suggested by Corya et al. were studied. The findings were compared with the indices of 20 healthy persons. The indices of regional and general contractile function of the left ventricle grew worse beginning with the first hours of the disease, the changes were most marked on the 3rd day while in cases with a fatal outcome they progressed or did not change. In cases with a fatal outcome they progressed or did not change. In cases with a favourable outcome, the indices improved gradually, first the volume/pressure coefficient and later the end diastolic index. The zones of asynergy disappeared before discharge in only 5 patients. Differences were found depending on the presence and severity of cardiac insufficiency and the localization of the myocardial infarction.