Limited data are available on the impact of concomitant left main coronary artery disease (CAD) on mortality after revascularization of multivessel coronary artery disease (MVD) alone or multivessel plus left main coronary artery disease (MVLMD). This study compared long-term mortality between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) with drug-eluting stents in 2,887 patients with MVD or MVLMD. Data were pooled from the BEST, PRECOMBAT, and SYNTAX trials. The primary outcome was death due to any cause. Of the 2,887 patients, 1,975 (68.4%) were classified as having MVD and 912 (31.6%) as having MVLMD. The median follow-up duration was 60.2 months. In the patients with MVD, primary outcome rate after CABG was significantly lower than after PCI (hazard ratio [HR] 0.66; 95% confidence interval [CI] 0.49 to 0.89; p = 0.007). In the patients with MVLMD, however, CABG and PCI showed similar primary outcome rates (HR 0.98; 95% CI 0.67 to 1.43; p = 0.896). Among those who underwent CABG, primary outcome rate was lower in the patients with MVD than in those with MVLMD (HR 0.66; 95% CI 0.46 to 0.95; p = 0.024). Kaplan-Meier analysis showed a clear separation between the patients with MVD and those with MVLMD 2.5 years after the index surgery. The risk of death due to any cause was significantly lower after CABG than after PCI with drug-eluting stents in patients with MVD but not in those with MVLMD. The advantage of CABG over PCI for multivessel CAD was significantly attenuated if concomitant left main CAD was present.