Cardiac rupture represents a fatal complication of acute myocardial infarction within the first two weeks. In exceptional cases, the postinfarction rupture of the myocardium is not transmural but remains circumscribed within the wall itself as a cavity joined to the left ventricle through a narrow neck. This finding is usually defined as pseudo-pseudoaneurysm. We report a rare case of postinfarction posterior pseudo-pseudoaneurysm of the left ventricle, perforated into the right ventricle. This unusual anatomy resulted, over a period of several years, by progressive intramural dissection of the surrounding necrotic myocardium with late formation of a large, partially fibrotic chamber, communicating either with left and right ventricles. Despite correct preoperative diagnosis was not achieved by 2D echocardiography, pulsed Doppler and contrast ventriculography, a successful surgical treatment was possible with a really good outcome.