Objectives: To assess sex differences in clinical presentation, in-hospital and long-term outcome in ST-elevated myocardial infarction (STEMI) patients undergoing primary PCI (PPCI)., Background: Several studies have shown higher rates of mortality in women. These differences are not always confirmed after adjusting for confounding variables., Methods: From January 2007 to December 2011, 325 consecutive patients (23.1% females and 76.9% males) were prospectively treated and retrospectively analyzed. Primary outcome was in-hospital and long-term mortality., Results: Women were older (71.8±11.7 vs. 62.5±12.6years; p<0.0001), presented more renal failure (45.3% vs. 20.8%; p<0.0001) and severe haemodynamic impairment (9.3% vs. 3.6%; p=0.04). In-hospital overall mortality (14.7% vs. 4.8%; p=0.003) and cardiac death (12% vs. 2%; p=0.002) were significantly higher in women. The multivariate analysis identified age (OR 1.07; 95% CI: 1.01-1.13), resuscitated cardiac arrest (CCA) and cardiogenic shock (CS) (OR 15.31; 95% CI: 4.30-61.75), renal failure (OR 0.20; 95% CI: 0.06-0.68), but not sex (OR 1.49; 95% CI: 0.53-4.22) as independent prognostic factors of in-hospital mortality. During a median follow-up of 46.5months (IQR range 32.7-63.1months), long-term overall mortality (24.2% vs. 11.0%; p=0.007) and cardiac death (4.8% vs. 1.7%; p=0.02) were significantly higher in women. The multivariate analysis identified age (HR 1.06; 95% CI: 1.02-1.11), previous AMI (HR 3.9; 95% CI: 1.63-9.35), renal failure (HR 5.21; 95% CI: 2.12-12.85), technical success (HR 0.35; 95% CI: 0.14-0.84) but not sex (HR 0.90; 95% CI: 0.42-1.94) as independent prognostic factors of long-term mortality., Conclusions: Worse clinical presentation rather than sex may explain the excess of mortality in women with STEMI undergoing PPCI., (Copyright © 2015 Elsevier Inc. All rights reserved.)