The long-term safety and efficiency of sirolimus-eluting stent (SES) treatment in unprotected left main coronary artery (ULMCA) have not yet been ascertained.From 2003 to 2006, 126 consecutive patients with de novo lesions in ULMCA who underwent SES were retrospectively analyzed in a single center in China. During 4-year follow-up, major adverse cardiovascular event (MACE)-free survival was 74.6%. Cardiac death occurred in 5 (4.0%), and target lesion revascularization (TLR) and target vessel revascularization (TVR) occurred in 15 (11.9%) and 24 (19.0%) patients, respectively. One (0.8%) experienced probable stent thrombosis while 1 (0.8%) presented possible stent thrombosis. Impaired LVEF (< 40%) and high surgical risk (Euro score > 6) were the independent predictors of MACEs.PCI with SES for de novo lesions in ULMCA is feasible with a low procedural risk. However, SES was associated with a relatively higher rate of TLR and TVR. Impaired LVEF and high surgical risk were important predictors of MACEs.