BACKGROUND. The aim of this study was to investigate the prognostic impacts of drug-eluting stents (DES) and bare-metal stents (BMS) in patients undergoing percutaneous coronary intervention (PCI) and risk factors of stent restenosis. MATERIAL AND METHODS. We conducted a retrospective cohort study based on the Angiographic diagnostic and treatment Department of 3rd State Central Hospital of Mongolia. Patients who had undergone coronary stenting between 2000 and 2017 were recruited and monitored until the end of 2010. RESULTS. Among a total of 4520 selected patients with a mean age of 58±7 years, 2125 subjects had BMS and 2395 subjects had DES. The incidence of stent restenosis and stent thrombosis were significantly lower in the DES (37; 1,5%) group as compared with the BMS (201; 9,4%) group. Patients who have stent restenosis presented comorbidities, such as diabetes 214(47,8%), hypertension 54(22,6%), prior PCI 21(8,2%), re-infarction 12(5,04%), chronic kidney disease 16(6,7%), hyperlipidemia 21(8,2%). СONCLUSION. Implantation of DES was related to better outcomes than for BMS, in terms of reducing restenosis and stent thrombosis after PCI. STEMI patients who have co morbidities have greater risk of stent stenosis and thrombosis