Introduction and objectives Surgical revascularization is the procedure of choice for unprotected left main coronary artery stenosis, but it may be unsuitable in some patients. We report short- and medium-term outcomes of percutaneous coronary intervention for unprotected left main coronary artery stenosis in a series of patients who were poor candidates for surgery. Patients and method Descriptive study of a historic cohort of consecutive patients with unprotected left main coronary artery stenosis who were not candidates for surgery, treated with percutaneous coronary intervention at a single center between April 1999 and December 2003. Results A total of 83 patients (mean age 72  years) were included. Twenty patients (24%) were in shock on presentation. Surgery was considered unsuitable because of unacceptable surgical risk, poor condition of the distal vessels or comorbid conditions in 61 (73.5%) patients, or acute myocardial infarction in 22 (27%). An intraaortic balloon pump was used in 34 (40%); abciximab in 30 (36%) and stenting in 79 (95%) procedures. The intervention was considered successful in 76 patients (92%). Total in-hospital mortality was 28.9% (55% in patients with acute myocardial infarction and 20% in those without acute myocardial infarction). Median follow-up was 17 months. Average survival was 19.7 (2) months. Eighteen (22%) patients were hospitalized again for a new ische-mic event, and 14 (17%) underwent revascularization. In 9 cases (10.8%) a new angioplasty was performed, and in 5 (6.0%) surgical revascularization was necessary. Conclusions Percutaneous coronary intervention is an option for revascularization in left main coronary artery stenosis in patients who are poor candidates for surgery, although in-hospital and long-term mortality remain high.