BACKGROUND: The benefit of primary percutaneous coronary interventions (P-PCI) for patients with ST-elevation myocardial infarction (STEMI) has been well documented. However, controversy still exists as to whether PCI should be expanded to hospitals without coronary artery bypass graft surgery. METHODS AND RESULTS: Patients who were discharged after PCI for STEMI between January 1, 2003, and December 12, 2006, in P-PCI centers (hospitals with no coronary artery bypass graft surgery, and PCI only for patients with STEMI) were propensity matched with patients in full service centers, and mortality and subsequent revascularization rates were compared. For patients undergoing PCI, there were no differences for in-hospital/30-day mortality (2.3% for P-PCI centers versus 1.9% for full service centers [P=0.40]), emergency coronary artery bypass graft surgery immediately after PCI (0.06% versus 0.35%, P=0.06), 3-year mortality (7.1% versus 5.9%, P=0.07), or 3-year subsequent revascularization (23.8% versus 21.5%, P=0.52). P-PCI centers had a lower same/next day coronary artery bypass graft rate (0.23% versus 0.69%, P=0.046) and higher repeat target vessel PCI rates (12.1% versus 9.0%, P=0.003). For patients with STEMI who did not undergo PCI, P-PCI centers had higher in-hospital mortality (28.5% versus 22.3%; adjusted odds ratio, 1.38; 95% CI, 1.10 to 1.75). CONCLUSIONS: No differences between P-PCI centers and full service centers were found in in-hospital/30-day mortality, the need for emergency surgery, 3-year mortality or subsequent revascularization, but P-PCI centers had higher repeat target vessel PCI rates and higher mortality rates for patients who did not undergo PCI. P-PCI centers should be monitored closely, including the monitoring of patients with STEMI who did not undergo PCI.