Stent thrombosis is a rare but potentially fatal complication of percutaneous coronary interventions (PCIs). In recent years, the predictive and prognostic value of the red cell distribution width (RDW) as an indicator of inflammation has been shown in many cardiovascular diseases. Aim of this study was to examine the predictive value of RDW for stent thrombosis in patients who underwent successful stent implantation for ST-elevation myocardial infarction (STEMI). In this retrospective study, 146 patients who underwent successful PCI to native coronary artery due to STEMI previously and presented with acute coronary syndrome with stent thrombosis were included (stent thrombosis group). A total of 175 patients who had similar procedural characteristics (type, diameter, and length of stent) and not had stent thrombosis were consisted control group. Patients were divided into tertiles according to the admission RDW values (12.9±0.4, 14.2±0.4, and 16.3±1.5, respectively). Stent thrombosis developed in 47 (40.9%) patients in the lowest tertile, 39 (37.9%) patients in mid tertile, and 60 (58.3%) patients in the highest tertile (P=0.006). Female gender ratio was statistically significantly higher in the 3rd tertile (13 [11.3%], 8 [7.8%], 24 [23.3%], P=0.003, respectively). RDW (OR: 1.397 [95% CI 1.177-1.657], P<0.001) and platelet count (OR: 1.008 [95% CI 1.004-1.012], P<0.001) remained independent predictors of stent thrombosis after multivariate logistic regression analysis. ROC curve analysis demonstrated that, admission RDW values higher than 13.9 can predict the development of stent thrombosis with a sensitivity of 57% and a specificity of 52% (The area under the ROC curve: 0.59 [95% CI 0.53-0.65] P=0.007). High RDW values found to be independently associated with the development of stent thrombosis in patients with STEMI.