UNLABELLED Heparin and enoxaparin possess anti-inflammatory properties. We compared the effects of these drugs on inflammatory biomarkers in patients with ST-segment Elevated Myocardial Infarction (STEMI). Thirty four patients with STEMI randomly separated in two groups and received standard doses of heparin and enoxaparin. The serum concentration of Serum Amyloid A (SAA), C-Reactive Protein (CRP), Interleukin (IL)-6, ferritin and Myeloperoxidase (MPO) were measured at baseline, 12 ,24 and 48 hours after drug administration. SERUM CONCENTRATIONS OF SAA (P 0.02), CRP (P: 0.02) and ferritin (P: 0.01) significantly reduced in heparin group during measurements compared to baseline, circulating levels of IL-6 (P: 0.002), SAA (P: 0.009), CRP (P: 0.01) were significantly decreased in enoxaparin group. The overall difference in inflammatory biomarkers between heparin and enoxaparin group was not significant. Both heparin and enoxaparine reduced serum levels of inflammatory biomarkers in patients with STEMI. This effect may provide additional clinical benefit of these drugs in the treatment of STEMI patients.