Despite utilizing optimal anticoagulant therapy during percutaneous coronary intervention (PCI), the incidence of periprocedural myocardial infarction (PPMI) remains 5 7% and evaluation of preprocedural clinical/angiographic characteristics has failed to reliably predict the likelihood of a PPMI. We hypothesized that immediate post-PCI assessment could identify a group of patients at very low risk for PPMI. A consecutive series of 258 PCI patients was stratified into 3 groups based on immediate post-PCI assessment. Group I (PPMI not expected) included those with an acceptable angiographic result of treated vessel (residual stenosis < 50%), TIMI 3 flow and absence of any intraprocedural complications. Group II (PPMI not unexpected) included those with an acceptable angiographic result, TIMI 3 flow but with any/all of the following: saphenous vein graft (SVG) PCI, transient closure of culprit vessel or major sidebranch, intracoronary thrombus, prolonged chest pain, electrocardiographic (ECG) changes, hypotension, resolved slow flow/no reflow, bailout glycoprotein IIb/IIIa inhibitor use, loss of a minor sidebranch or any angiographic residual stenosis > 50% with TIMI 3 flow. Group III (PPMI expected) included those with any angiographic result of native coronary artery or SVG with < TIMI 3 flow, unresolved chest pain, hypotension or ECG changes at the end of the PCI, loss of a major sidebranch or vessel, or persistent no-reflow. Group stratification was analyzed in relation to the incidence of PPMI (CK-MB > 3 times the upper limit of normal; 18 24 hours post-PCI). Rate of PPMI: Group I (1/141; 0.7%), Group II (7/71; 9.9%), Group III (5/11; 45.5%) (p < 0.001). The 3 groups did not differ in age, clinical presentation or stent use (p = NS). Sixty out of 105 patients (57.1%) with unstable angina, seventy-seven out of 146 patients (52.7%) with B2/C lesions, and 105/180 patients (58.3%) with unstable angina or B2/C lesions were stratified to Group I. This study demonstrates that immediate post-PCI evaluation of the clinical/angiographic characteristics can predict the likelihood of PPMI and a group of patients at a very low risk for a PPMI can be identified, in whom implications exist for limited hospitalization and post-procedural antithrombotic therapy.