The purpose of this randomized trial was to evaluate the role of debulking and balloon predilation on acute and long-term results of stent implantation in diffuse stenosis of small vessels. Patients with symptomatic diffuse stenosis of the native left anterior descending coronary artery between 2 and 2.9 mm in size were randomly assigned to rotational atherectomy (group I, n=21) or balloon dilation (group II, n=20) before stenting. The primary end point of the study was the incidence of angiographic restenosis at follow-up; adverse clinical events, such as death, myocardial infarction, stroke, or target vessel revascularization, were assessed as secondary end points. Acute gain was significantly greater in group I than in group II (p =0.038), but net gain at follow-up was similar in both groups (p =0.24). There was no significant difference in angiographic restenosis rate (33.3% vs 31.3%, p=0.80), target vessel revascularization (23.8% vs 15%, p=0.21) or 1-year event-free survival rate (72.8% vs 84.6%, p=0.28). In conclusion, rotational atherectomy before stenting showed no additional benefit over balloon dilation with stenting in the management of diffuse lesions in small coronary vessels.