The baseline platelet count (BPC) in patients with acute ST elevation myocardial infarction (STEMI) may reflect the baseline anjiografic finding and may also predic long-term outcomes after primary percutaneous coronary intervention (PPCI). Available data for the value of BPC in patients with STEMI treated with PPCI are still questionable. Therefore, we sought to determine the prognostic value of BPC for baseline angiographic finding and the impact of BPC on clinical outcomes of patients treating with PPCI. Blood sample for BPC was obtained on admission in 140 consecutive patients undergoing PPCI. Patients were divided 2 groups that group-1 (104 patients): TIMI flow-grade 0 and group-2 (36 patients): TIMI flow-grade 1-3. Follow-up was performed at 1-9 months. Baseline demographics were comparable, but, BPC was significantly higher in group-1 comparing 2 (293.7 +/- 59.8x10(9)/L vs. 237.7 +/- 50.9x10(9)/L, p<0.0001), pre-procedural lesion length longer in group-1 comparing 2 (13.6 +/- 3.6 mm vs. 11.4 +/- 3.9 mm, p:0.003). Distal embolization (19.0% vs. 0.0%, p:0.001), slow-flow (15.2% vs. 2.9%, p:0.033) were more common in group-1 and mean maximum troponin-I level (9.1 +/- 4.2 mu g/L vs. 5.1 +/- 3.9 mu g/L, p<0.0001) and mean maximum creatinin kinase (2077.6 +/- 1378.4 U/L vs. 1163.4 +/- 869.7 U/L, p:<0.0001) were higher in group-1. In-hospital and 30-days major cardiac adverse events (MACEs) (16.5% vs. 5.7%), p: 0.14) were similarly in both groups, but, at 6-months target vessel revascularization (13.9% vs. 0.0%, p:0.017) and MACEs significantly higher in the group-1 (24.1% vs. 2.9%, p:0.013). Conclusion: A higher BPC without any antithrombotic agent is a strongly predictor of total occlusion of IRA in STEMI treated with PPCI. And a higher BPC associated with poor clinical outcomes at 9-months. Apart from prognostic value, measuring of a BPC on admission may also provide further practical and therapeutic profits.