Transradial percutaneous coronary intervention (PCI) is a safe and effective method of percutaneous revascularization. However, there are no data on the efficacy of the transradial approach in left main (LM) PCI. We studied 80 patients (pts) who underwent LM PCI between February 1994 and January 2002, and compared the radial (27 pts) and femoral (53 pts) approaches. Patients were considered free of restenosis if they were free of angina and had a negative treadmill or nuclear imaging study 6 months post-PCI. Mean follow-up time was 27.4+/-23.0 months. Reason for PCI (stable angina, unstable angina, acute myocardial infarction) and lesion location (ostial, mid, distal) were similar in both groups (p>0.05), whereas mean ejection fraction was higher in the radial group (56.5+/-11.1% versus 49.2+/-14.7%, respectively; p<0.05). Sheath size (7 or 8 French; 44.4% radial versus 77.3% femoral) and amount of heparin used (9,192+/-3,645 IU versus 11,468+/-5,083 IU) were significantly larger in the femoral group (p<0.05), and the use of intra-aortic balloon pump was significantly more frequent (3.7% versus 22.6%). Mean fluoroscopy time (21.3+/-12.8 minutes versus 16.7+/-8.5 minutes), amount of contrast used (227+/-92 ml versus 225+/-85 ml), mean procedural time (67.0+/-27.6 minutes versus 73.4+/-32.7 minutes), procedure success (96.3% versus 98.1%), in-hospital major adverse cardiac events (MACE; 7.4% versus 5.6%) and 6-month MACE (14.8% versus 25.5%) were similar in the 2 groups (p>0.05). However, major vascular complications occurred only in the femoral group (5.7%). Radial LM PCI is as fast and successful as the femoral approach and results in fewer vascular complications.