Background Red blood cell transfusion after coronary artery bypass graft surgery has been associated with increased late all-cause death. Yet, whether this association is, first, independent of the packed red blood cells and perioperative morbidity association, and second, of a cardiac versus noncardiac etiology remains unknown. Methods We analyzed patients undergoing coronary artery bypass graft surgery at two Ohio hospitals (n = 6,947) from 1994 to 2007. Salvage operations and patients with preoperative renal failure were excluded. Long-term outcomes and leading cause of death (cardiac, noncardiac, all cause) were derived from the US Social Security Death Index and later from Ohio Department of Health Death Index. Fifteen-year mortality cumulative incidence functions were compared for transfusion groups (yes, n = 2,540; no, n = 4,806) overall, and then stratified based on perioperative complications status (yes, n = 2,638; no, n = 4,708). Comprehensive, 32 covariates, risk-adjusted transfusion effects were estimated by competing risk regression. Results were confirmed by propensity score adjusted analysis. Results Perioperative transfusions and complications occurred in 33.9% and 35.2% of patients, respectively. In all, 3,108 deaths (48.1%) have been documented (median time to death, 7.43 years). Both transfusion rates (25.6% versus 49.1%, p p Conclusions Perioperative red blood cells transfusion is associated with significant adverse late death effects among both complicated patients and noncomplicated patients, principally seen between 0 and 5 years postoperatively, and is driven by both increased cardiovascular and noncardiovascular mortality. Further studies are needed to elucidate the mechanisms behind these findings, including their potential dose dependence.