BACKGROUND Off-pump coronary artery bypass grafting (CABG) has been performed since 1996 in our institute, and its application has recently been expanded to patients with three-vessel disease. A study was performed to clarify the benefit of off-pump CABG for patients with three-vessel disease. METHODS Between June 1, 1991 and September 30, 2001, a total of 1089 patients with three-vessel disease (832 men and 257 women; mean age, 64.0 +/- 9.1 years) underwent on-pump CABG. After 1997, a total of 310 patients with three-vessel disease (223 men and 87 women; mean age, 68.8 +/- 8.6 years) underwent off-pump CABG. Data of the historical cohort of on-pump CABG and the concurrent cohort of off-pump CABG were analyzed retrospectively. RESULTS The 2 groups were age and gender matched. Significant comorbidities were more often observed in the off-pump group than in the on-pump group. The mean number of bypass grafts in the off-pump versus on-pump CABG was 3.3 vs 3.7, P <.0001. The mean intubation period, intensive care unit stay, and postoperative hospital stay were 7.9 vs 11.7 hours, 2.2 vs 3.0 days, and 14.5 vs 17.5 days, respectively (P <.0001). In-hospital mortality rate (0.6% vs 1.2%, respectively) and morbidity rates (10.3% vs 12.9%, respectively) were not significantly different. After surgery, calculated event-free rates at 2 years were 93.3% vs 91.9%, respectively; P = not significant. CONCLUSIONS In patients with multivessel disease, off-pump CABG provided early recovery, and its complication rates and early follow-up results were equivalent to on-pump CABG.