Background Compared with angioplasty, elective stent implantation has improved short-term and long-term outcome with a decrease in abrupt closure and a reduced 6-month restenosis rate. Although primary angioplasty during acute myocardial infarction has improved outcome, recurrent ischemic events and restenosis are still a problem. Methods Outcomes for 166 consecutively treated patients who underwent stent insertion procedures within 24 hours after the onset of acute myocardial infarction were compared with those for a similar group of patients (n = 212) who underwent consecutive balloon angioplasty procedures at one tertiary care institution. The objective of this study was to examine in-hospital and late clinical outcomes for the 2 groups. Results The procedural success rate for stenting in acute myocardial infarction was 100%; that for angioplasty was 98%. Mortality rates during hospitalization were similar for the stent group and the angioplasty group (4.0% vs 2.0%). The rate of in-hospital acute reocclusion necessitating urgent percutaneous reintervention was significantly lower for the stent group (0% vs 3%, P = .02). Six months after the procedure, the stent group had a significantly lower need for revascularization of the infarct-related artery (8% vs 20%, P = .001) and a significantly lower incidence of combined serious clinical events (death, acute occlusion, emergency bypass, target vessel revascularization, and nonfatal myocardial infarction; 12% vs 30%, P = .00003). Conclusion Compared with balloon angioplasty, stent deployment in the setting of acute myocardial infarction was associated with significantly lower frequency of in-hospital acute occlusion and significantly less need for target-vessel revascularization 6 months after myocardial infarction. (Am Heart J 2000;139:44-51.)