We assessed the perioperative pattern of serum ischemia-modified albumin and its role as a myocardial ischemia indicator for early detection of perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting. Venous blood samples were collected from 63 consecutive patients before the operation, immediately after the operation, and at 3, 6, 12, and 24 h postoperatively. Serum ischemia-modified albumin levels were analyzed using an albumin cobalt binding test. The patients were divided into 2 groups retrospectively, according to the occurrence of perioperative myocardial infarction. The serum ischemia-modified albumin levels were compared between groups. The levels peaked immediately after the operation, followed by a gradual regression, but remained elevated during the first 24 h in all patients. The occurrence of perioperative myocardial infarction was identified in 10 patients who had significantly higher ischemia-modified albumin levels at 3 h postoperatively and slower regression rates. Perioperative serum ischemia-modified albumin levels might be helpful in predicting perioperative myocardial infarction.