Two patients in whom myocardial infarction in the inferior wall occurred after off-pump coronary artery bypass grafting (OPCAB) are described. In both patients, the right coronary artery had no critical lesion and was not grafted. There was no ischemic episode during operation. Coronary artery spasms and/or intracoronary thrombus formation may have been causes of these events. To our knowledge, this is the first report on perioperative myocardial infarction in OPCAB.