['The authors aimed to investigate whether immediate postoperative hypoalbuminemia could be associated with outcomes after off-pump coronary artery bypass graft (OPCAB) surgery.', 'A retrospective analysis of the medical data.', 'Cardiac operating room and adult cardiovascular intensive care unit at a single institution.', 'Six hundred ninety adult patients underwent elective OPCAB surgery over a 30-month period.', 'None.', 'To evaluate the clinical relevance of immediate postoperative hypoalbuminemia, the lowest serum albumin level measured over the first 12 hours postoperatively was recorded. A cutoff point was calculated by the area under the curve in the receiver operating characteristic plot for 30-day adverse events including death. Patients were classified according to the cutoff value, and outcomes were compared between groups using propensity score-matching analysis. The impact of immediate postoperative hypoalbuminemia on OPCAB outcome was investigated using multivariate analysis. The cutoff value for immediate postoperative albumin concentration for predicting 30-day adverse events was 2.3 g/dL. Immediate postoperative hypoalbuminemia (<2.3 g/dL) was associated independently with postoperative respiratory failure (odds ratio [OR] = 8.85, p = 0.04), wound infection (OR = 4.44, p = 0.04), the need for an intra-aortic balloon pump after the operation (OR = 13.7, p = 0.02), renal failure (OR = 7.98, p = 0.01), reoperation for bleeding (OR = 4.33, p = 0.05), and the need for inotropes in the intensive care unit (OR = 1.79, p = 0.02).'] Is postoperative hypoalbuminemia associated with outcome in patients undergoing off-pump coronary artery bypass graft surgery?