Six morphologic variants of hypertrophic cardiomyopathy (HCMP) have been identified on the basis of the echocardiographically-documented extent and localization of left-ventricular hypertrophy in 34 patients with HCMP. More than half of the patients had no complaints. The more characteristic echocardiographic features of the disease included a considerable thickening of one or more departments within the left ventricle, the size of its cavity being diminished. In most cases, HCMP was associated with considerably enlarged R waves on the electrocardiograms from 35 precordial leads that were usually combined with ST segment depression and T wave inversion. The latter two features often provided grounds for a hyperdiagnosis of coronary heart disease (CHD). What distinguishes HCMP from CHD is the discrepancy between marked and persistent pathologic electrocardiographic changes and a relatively uneventful clinical picture of the disease. The comparison of echocardiographic and ECG charting data allows a more detailed assessment of the kind of left-ventricular hypertrophy in HCMP patients, and can be used in the differential diagnosis of HCMP vs. CHD.