Acute myocardial infarction (AMI) is a life threatening condition that needs emergency diagnosis and early treatment in the emergency room. Rapid laboratory testing for creatine kinase (CK)-MB greatly revolutionized the diagnosis and management of acute myocardial infarction. We report a case with chest pain that referred to the emergency department (ED). Laboratory data showed high serum levels of creatine kinase and lactate dehydrogenase. With diagnosis of acute myocardial infarction, he was hospitalized and angiography was performed which showed three vessels disease; the patient was referred to surgical ward for coronary artery bypass graft. Surgery was performed after one week; during the operation there was no sign of infarction over the heart. Our observation suggests that false positive laboratory result may be due to other condition which must be evaluated.