Abstract: Background: Mortality in female patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary angioplasty (pPCI) is higher than in men. We examined gender differences in the prevalence and prognostic performance of renal dysfunction at admission in this setting. Methods: A multicenter retrospective sub-analysis of the Belgian STEMI-registry identified 1,638 patients (20.6% women, 79.4% men) treated with pPCI in 8 tertiary care hospitals (January 2007-February 2011). The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Main outcome measure was in-hospital mortality. Results: More women than men suffered from renal dysfunction at admission (42.3% vs. 25.3%, p < 0.001). Mortality in women was doubled as compared to men (9.5 vs. 4.7%, OR (95% CI) = 2.12 (1.36-3.32), p<0.001). In-hospital mortality for men and women with vs. without renal dysfunction was much higher (10.7 and 15.3 vs. 2.3 and 2.4%, p < 0.001). In a multivariable regression analysis, adjusting for age, gender, peripheral artery disease (PAD), coronary artery disease (CAD), hypertension, diabetes and low body weight (< 67 kg), female gender was associated with renal dysfunction at admission (OR (95% CI) 1.65 (1.20-2.25), p = 0.002). In a multivariable model including TIMI risk score and renal dysfunction, renal dysfunction was an independent predictor of in-hospital mortality in both men (OR (95% CI) = 2.39 (1.27-4.51), p = 0.007) and women (OR (95% CI) = 4.03 (1.26-12.92), p = 0.02), with a comparable impact for men and women (p for interaction = 0.69). Conclusions: Female gender was independently associated with renal dysfunction at admission in pPCI treated patients. Renal dysfunction was equally associated with higher in-hospital mortality in both men and women.