Rupture of the ventricular septum in the acute phase of myocardial infarction (MI) requires prompt recognition for correct management. The 2-dimensional and pulsed Doppler echocardiographic findings are reported from 11 patients with ventricular septal (VS) rupture. VS rupture was confirmed by cardiac catheterization in 9 patients, surgery in 4 patients and necropsy examination in 3 patients. Two-dimensional echocardiography (echo) directly visualized the rupture in 7 patients and assessed the size and location of an associated aneurysm in 10. In all patients, M-mode pulsed Doppler echo allowed detection of the left-to-right shunting due to VS rupture, but failed to indicate the rupture site. M-mode pulsed Doppler echo was reliable for detecting VS rupture after MI. Conversely, 2-dimensional echo was less effective in the direct visualization of the rupture, but provided anatomic and functional information that was useful in medical and surgical management. Thus, the techniques are complementary and should be used in combination for the assessment of VS rupture in acute MI.