In a group of 59 patients with hypertrophic cardiomyopathy relationship between echocardiographic parameters (interventricular septal thickness, left ventrical diastolic diameter, presence of SAM, distribution of hypertrophy) and certain hemodynamic measurements (diastolic compliance, left ventricular end-diastolic pressure, intraventricular pressure gradient, mean wall thickness and left ventricular mass index) were assessed. Substantial elevation of left ventricular end-diastolic pressure (LVEDP greater than 20 mmHg) was significantly more prevalent among patients with small left ventricular diameter and gross septal hypertrophy. Extensive ventricular hypertrophy (Maron type III) was not characterized by any distinctive hemodynamic pattern. Presence of SAM reaching interventricular septum was indicative of left ventricular outflow obstruction.