Although use of bare metal stents has reduced restenosis in coronary vessels with a diameter ≥3 mm when compared to plain balloon angioplasty, most of the dedicated randomized studies have failed to show a beneficial effect of stent over balloon angioplasty in vessels with a small reference diameter. In spite of refinements in stent design and periprocedural therapy, the risk of restenosis after bare metal stenting in this setting remains elevated. Nowadays, percutaneous coronary interventions in small vessels account for 35-67% of interventional procedures performed in patients with coronary artery disease and, when bare metal stents are used, restenosis will be detected in more than 35% of the treated patients and a repeat revascularization procedure will be needed in more than 20% them. Several randomized trials have shown that stents eluting antiproliferative drugs, with sirolimus- and paclitaxel-eluting stents the only devices approved for commercial use so far, are highly effective in reducing restenosis when compared with bare metal stents. Subgroup analysis from these trials have shown that the efficacy of either sirolimus stent or paclitaxel stent extends also to those patients who undergo coronary stenting in small sized vessels. In addition, three randomized studies of sirolimus-eluting stents and bare metal stents used in coronary arteries smaller than 3 mm have reported 82-96% reduction in the relative risk of restenosis with the sirolimus stents thus, providing convincing evidence on the role of drug-eluting stents as an effective treatment strategy for coronary arteries with a small reference diameter.