Randomized clinical trials have demonstrated that coronary stenting is more successful than balloon angioplasty in improving short- and long-term outcomes. However, it remains unknown whether those results can be generalized to broad-based practice. This study aimed to determine whether the outcome for patients with acute myocardial infarction (AMI) undergoing coronary stent placement would be better than those undergoing balloon angioplasty. The risk-adjusted mortality and subsequent revascularization rates were compared for 2,185 patients from a nationwide Japanese registry during 1997. A total of 1,349 patients were treated with balloon angioplasty alone and 836 had stent placement. There were no statistically significant differences in the prevalence of demographic, clinical, and angiographic variables, except that the angioplasty group had a greater proportion of female patients and those with a left circumflex lesion. Unadjusted in-hospital mortality was comparable (7.6 vs 6.3%; p=0.28), despite higher angiographic success rate for the stent group (89.7 vs 97.7%; p<0.01). Adjusted odds ratio for in-hospital mortality was 0.75 (p=0.19). The same-admission bypass surgery rate was also similar. The 1.9-year post-discharge mortality rate was similar. The need for subsequent revascularization procedures was also similar, but restenosis was significantly lower in the stent group (34 vs 45%; p<0.01). The superiority of clinical outcome for stenting rather than balloon angioplasty could not be demonstrated in broad-based registry patients, despite technically successful results. (Circ J 2003; 67: 369 - 374)