Early infarct-related artery (IRA) patency is associated with better clinical outcomes in patients with ST-elevation myocardial infarction (STEMI). Using the French Registry of ST-elevation and non–ST-elevation Myocardial Infarction (FAST-MI) 2010 registry, we investigated factors related to IRA patency (thrombolysis in myocardial infarction TIMI 2/3 flow) at the start of procedure in patients admitted for primary percutaneous coronary intervention. FAST-MI 2010 is a nationwide French registry including 4,169 patients with acute MI. Of 1,452 patients with STEMI with primary percutaneous coronary intervention, 466 (32%) had TIMI 2/3 flow of IRA before the procedure. Mean age (62 ± 14 years in both groups), Global Registry of Acute Coronary Event score (141 ± 31 vs 142 ± 34), and time from onset to angiography (472 ± 499 vs 451 ± 479 minutes) did not differ according to IRA patency (TIMI 2/3 vs TIMI 0/1). Using multivariate logistic regression analysis, IRA patency was more frequently found in patients having called earlier (time from onset to electrocardiogram ECG <120 minutes; odds ratio OR 1.49; 95% confidence interval CI 1.17 to 1.89), or receiving rapid-onset of action (prasugrel or glycoprotein IIb-IIIa) antiplatelet therapy in the prehospital setting (OR 1.59, 95% CI 1.14 to 2.21). Increasing time from diagnostic ECG to angiography was also associated with IRA patency (>90 minutes; OR 1.37, 95% CI 1.08 to 1.75). In conclusion, preprocedural IRA patency is observed in one third of patients with STEMI, it is more frequently found in patients having received fast-acting antiplatelet therapy before angiography, and in patients having called early. Higher IRA patency with increasing time delays from qualifying ECG to angiography suggests an additional role of spontaneous or medication-mediated fibrinolysis.