Objectives: To assess the prognostic significance of circulating endothelial progenitor cells (EPCs) level and indices of endothelial damage/dysfunction in acute ST-elevation myocardial infarction (STEMI).Background: EPCs level increases in the early phase after STEMI. Methods: In 85 consecutive patients with acute STEMI, the number and function of peripheral blood CD31+/CD34+ EPCs, as well as the indices of endothelial damage/dysfunction [vWF and flow mediated dilatation (FMD)] were determined. The primary end point was a composite of all-cause mortality, recurrent nonfatal MI, or heart failure (MACEs) during follow-up period of 30 days, with the echocardiographically assessed 30 day-left ventricular (LV) remodeling as the secondary end point.Results: During the follow-up, MACE occurred in 17 (22%) patients. EPC level (p =0.004) and vWF (p =0.03) were significantly higher, however, FMD was significantly lower (p =0.006) in the MACE-group compared to non-MACE-group. Multivariate analysis showed that EPC level and LV ejection fraction were the most independent predictor of MACE. There was significant correlation between the EPC level and function in the low EPC-group (level ≤ 82%) and not in the high EPC-group (level > 82%). The areas under the receiver-operating characteristic curve (AUC) for EPC level, FMD, and the logistic model with both markers were 0.73, 0.75, and 0.82 respectively. There was significant increase in LV end-diastolic volume baseline-to-follow-up in the high EPC-group and not in low EPC-groupConclusions: High level of circulating EPCs predicts the occurrence of MACE and early adverse remodeling, with the FMD complements the EPC level to improve risk stratification.