Myocardial free wall rupture accounts for between 8% and 17% of mortality after myocardial infarction. In up to 40% of cases death occurs subacutely over a matter of hours, not minutes. Illustrative clinical cases and data suggest that a high degree of clinical suspicion, along with the early use of echocardiography, could significantly reduce mortality resulting from myocardial free wall rupture complicating myocardial infarction. Myocardial free wall rupture should be suspected in patients with recent myocardial infarction who have recurrent or persistent chest pain, hemodynamic instability, syncope, pericardial tamponade, or transient electromechanical dissociation. In this clinical situation, emergent echocardiography showing a pericardial effusion or pericardial thrombus is highly suggestive of free wall rupture. Surgical exploration and rupture repair is the definitive diagnostic and therapeutic procedure.