We reviewed the records of 50 consecutive patients presenting with sternal fracture after blunt chest trauma. The relationships between electrocardiogram, creatine kinase MB isoenzyme and echocardiogram (ECHO) were assessed in reference to myocardial contusion. Eleven patients (22%) had 1 or more abnormal cardiac tests but only 3 (6%) had clinically symptomatic myocardial contusion. Seven (22.5%) out of 31 ECHO studies revealed pericardial effusion which was not associated with the severity of all other associated injuries. The incidence of an abnormal ECHO study in patients with isolated sternal fracture was similar to that of patients who suffered multiple injuries. In 5 patients with pericardial effusion, this finding was not associated with any other abnormal tests and was regarded as of no clinical cardiac significance. On the other hand, a myocardial contusion was shown by ECHO examination only while echocardiogram and creatine kinase MB tests remained normal in that patient. We suggest that the ECHO should be used as a diagnostic and triage tool in every patient with sternal fracture associated with other injuries. However, patients with "benign" pericardial effusion can be discharged as soon as their medical condition improves regardless of other associated injuries.