The recent SCORES trial demonstrated that lower dilatation pressures seen with self-expanding (SE) stents may be associated with lower rates of target lesion revascularization (TLR). To determine whether SE stents with low-pressure dilatation are as safe and effective as balloon expandable (BE) stents. We randomly assigned 254 patients with 279 coronary lesions to groups receiving either SE with low-pressure dilatation <12 atm (n = 143) or conventional BE stents (n = 136). Thereafter, acute results and long-term outcomes were compared. Baseline patient and angiographic characteristics were similar in two groups. The incidence of procedural complications, such as slow flow, side branch occlusion, and edge dissection were significantly lower in the SE group than in the BE group (overall: SE, 17; BE, 35; P < 0.01), and the occurrence of myocardial infarction tended to be lower in SE than in BE (SE, 1; BE, 4; not significant). Although acute gain was significantly smaller with SE than BE (SE, 2.21 +/- 0.65 mm; BE, 2.42 +/- 0.62; P < 0.01), probably due to gradual expansion of the SE stent, nearly identical minimum luminal diameters on follow-up angiography (SE, 2.14 +/- 0.92 mm vs. BE, 2.22 +/- 0.93; not significant) and similar angiographic restenosis (SE, 18.1% vs. BE, 20.5%). and TLR rates (SE, 16.1% vs. BE, 14.0%) were apparent. This prospective randomized trial demonstrates that SE stents with low-pressure dilatation is safe and effective strategy for treating coronary arterial stenosis.