BACKGROUND: The objective was to evaluate the impact of complete revascularization (CR) versus reasonable incomplete surgical revascularization (IR) in others than left anterior descending artery territory on early and late survival in patients with multivessel coronary artery disease (CAD). METHODS AND RESULTS: During a 7-year period, 8.806 consecutive patients with multivessel CAD affecting the proximal left anterior descending artery or left main stem underwent sternotomy for isolated coronary artery bypass grafting including left internal mammary artery-left anterior descending artery bypass. A total of 936 patients (10.6%) had IR of the circumflex or right coronary artery territory. IR was based on the traditional classification. Follow-up was 3.5+/-2.2 years. Patient groups were comparable regarding age (CR 67.1 versus IR 67.6 years), ejection fraction (57.2% versus 57.5%), and logEuroscore (4.5% versus 4.5%). Patients receiving IR presented with more complex CAD. Mean number of distal anastomoses was 3.0+/-0.8 CR versus 2.4+/-0.6 IR. Operation time (176 versus 187 minutes) and cross-clamp time (52 versus 56 minutes) were longer in the IR group (P<0.001). Hospital mortality was 3.3% CR versus 3.2% IR (P=0.520). Independent risk factors for hospital mortality were age, pulmonary hypertension, chronic obstructive pulmonary disease, peripheral vascular disease, and emergency indication, but not IR (P=0.922). Arterial revascularization was protective. Cumulative survival at 1-year was 93.1% CR versus 93.6% IR and at 5 years 82.2 CR versus 80.9% IR (P=0.457). CONCLUSIONS: In presence of left internal mammary artery-to-left anterior descending artery bypass, reasonable IR of the circumflex or right coronary artery territory did not adversely affect early or long-term survival in patients with multivessel CAD. In patients presenting with 1 poor target vessel; however, IR is a good therapeutic option and the benefit of CR should be balanced against the risks.