Usefulness of two-dimensional and Doppler echocardiography in diagnosis of the ruptured interventricular septum in a course of myocardial infarction was evaluated basing on own material consisted of 6 cases. Ventricular septal defect was visualized in 5 patients. The blood flow through the ventricular septum was detected in all of 6 patients. Obtained results were concordant with intraoperative and anatomicopathologic findings as for as the localization of the rupture is concerned.