Two rare mechanical complications of right ventricular infarction are reported: myocardial dissection and rupture of the RV free wall. The diagnosis was made by 2D echocardiography in both cases. Myocardial dissection resulted in the formation of an oblong, expansive, intraparietal space. The rupture of the RV free wall was visualised as a breach of the continuity of the ventricular wall. These cases underline the importance of 2D echocardiography in the acute phase of myocardial infarction for the diagnosis of these complications.