Background: Sirolimus-eluting stent implantation improves the outcome in simple coronary artery lesions compared with bare metal stents, but there is limited evidence of their safety and efficacy when implanted in complex lesions like coronary bifurcations. Methods: SCANDSTENT was a randomized controlled study comparing implantation of sirolimus-eluting stents with bare-metal stents in patients with complex coronary artery disease. This substudy evaluates the angiographic and clinical outcome of 126 patients with lesions located in a coronary bifurcation. Results: The baseline characteristics of the patients were comparable: 15% had diabetes, and 1.7 stents were implanted per lesion. At follow-up, the minimum lumen diameter of the main branch was 2.35 mm in patients who received sirolimus-eluting stents compared with 1.68 mm in those who received bare-metal stents, and that of the side branch was 1.70 versus 1.19 mm (both P < .001). The late lumen loss in the main branch was 0.12 mm in the sirolimus-eluting stent group versus 0.99 mm in the bare-metal stent group and 0.03 versus 0.56 mm in the side branch (both P < .001). Thus, sirolimus-eluting stents reduced the restenosis rate from 28.3% to 4.9% in the main branch and from 43.4% to 14.8% in the side branches (both P < .001). Major adverse cardiac events occurred in 9% with sirolimus-eluting stents versus 28% with bare-metal stents (P = .01), and stent thrombosis was observed in 0% versus 9% (P = .02). Conclusion: Sirolimus-eluting stent implantation improves both the angiographic and clinical outcomes considerably compared with that of bare-metal stents in patients with stenoses located in coronary bifurcations.