Although many different tests are used to diagnose myocardial contusion, the clinical implications of the diagnosis are unclear. This makes it difficult to decide which patients require admission to a monitored bed. During 16 months, 3010 patients with blunt trauma were reviewed for evidence of sequelae attributable to myocardial contusion. None of 2204 admissions to unmonitored beds had evidence of serious arrhythmias or heart failure. No patient who died after admission had myocardial contusion at autopsy. Of the 644 admissions to monitored beds, 95 had workups for suspected contusion. Heart failure not obvious on admission did not occur and there were only four arrhythmias that required treatment. Conduction abnormalities on admission electrocardiogram predicted serious arrhythmias. Echocardiography and creatine phosphokinase isoenzyme levels, although frequently positive, did not predict morbidity. Clinically significant myocardial contusions are rare. Patients who will develop life-threatening complications from blunt cardiac injury can be identified in an emergency room setting.