Vitamin D displays a broad spectrum of cardioprotective effects, preventing oxidative stress, inflammation and thrombosis and improving endothelial function. Previous studies have associated vitamin D deficiency with more extended and severe coronary artery disease (CAD) and worse outcome, and especially among patients with ST-segment elevation myocardial infarction (STEMI). However, few data have been reported on the association of vitamin D levels with the angiographic findings and epicardial reperfusion in STEMI patients undergoing primary percutaneous coronary intervention (pPCI), that was therefore the aim of the present study.