Background: Primary PCI (PPCI) with noreflow (NR) has been previously associated with worse outcomes. Objectives: We aimed to identify the prevalence of NR in patients with ST elevation myocardial infarction (STEMI) undergoing PPCI in the current era and its predictors with short term outcome. Methods: This prospective study enrolled 310 consecutive STEMI patients underwent PPCI. Patients were divided into 2 groups: patients with normal flow and others with NR whose (final TIMI flow <3 in the absence of coronary dissection or spasm) compared for demographic, procedural characteristics, ST resolution and short term outcomes. Results: 293 patients were finally included. NR was observed in 91 (31.06%) patients. The occurrence of NR was associated with higher mortality (25.3% vs. 3%, P=0.003) compared to patients with normal flow. Multivariate logistic regression analysis showed that high thrombus burden (thrombus grade ≥4), reference luminal diameter ≥3 mm, symptoms to first medical contact time ≥4h, anterior infarctions and syntax score ≥19 were independent predictors of NR. Using thrombus aspiration was found to be protective against NR only in patients with high thrombus burden which was associated with mortality reduction. Conclusion: In the contemporary era of PPCI, NR is more likely to occur in patients with high thrombus burden presenting late and is still associated with marked increases in adverse outcomes. Thrombus aspiration can prevent NR in patients with high thrombus burden.