We tested the hypothesis that selected prothrombotic biomarkers might be associated with early spontaneous coronary recanalization in patients with ST-segment elevation acute myocardial infarction (STEMI). We prospectively enrolled 123 patients with STEMI including 53 patients with spontaneous coronary recanalization (cases) and 70 patients with persistent occlusion (controls) at the time of emergent coronary angiography and before angioplasty. All had received aspirin and heparin. Blood samples were collected immediately before angioplasty to measure soluble P-selectin, circulating microparticles originating from platelets (PMPs), granulocytes (GMPs), endothelial cells (EMPs); tissue factor-associated MP (TF-MP); soluble platelet glycoprotein V (sGPV) and prothrombin F1 + 2; tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1) and plasmin-antiplasmin (PAP). A sub-group of 70 patients (35 cases, 35 controls) was available for flow cytometry analysis of platelet P-selectin and activated GPIIb-IIIa. Baseline clinical characteristics did not differ between groups except for more frequent hypertension and dyslipidemia in controls. Platelet activation markers and PMP did not differ between the two groups. Controls had higher numbers of EMPs and GMPs compared to cases, but the difference was no longer significant when corrected for risk factors. Controls differed from cases by higher plasma levels of sGPV [64 (47-84) ng/ml vs. 53 (44-63) ng/ml] and PAP [114(65-225) ng/ml vs. 88 (51-147) ng/ml]. The difference persisted after adjustment for risks factors (p = 0.031 and 0.037, respectively). Persistent occlusion of the infarct related artery is associated with some markers related to higher thrombin (sGPV) and plasmin (PAP) production but is not associated with markers of platelet activation.