Interventricular septal rupture is a rare complication of the acute myocardial infarction. We report a case with rupture 4 weeks after diaphragmatic wall necrosis. The patient developed heart failure, precordial murmur and clinical signs of left-to-right shunt. The septal rupture was detected by two-dimensional echocardiogram and confirmed by catheterization. The surgical correction of the defect, was successful.