Aim. To evaluate the efficacy and safety of intracoronary epinephrine for the treatment of refractory no-reflow phenomenon in patients with ST-segment elevation myocardial infarction (STEMI) during percutaneous coronary intervention (PCI).Material and methods. A single-site prospective controlled study “Intracoronary administration of epinephrine for refractory no-reflow phenomenon in patients with acute myocardial infarction” was conducted (registration on ClinicalTrials.gov: NCT04573751). The study included 40 patients with refractory no-reflow phenomenon, which was identified when it was not resolved with at least one of the following means: nitroglycerin, adenosine, papaverine, platelet receptor inhibitors IIB/IIIA, or thromboaspiration. Patients were divided into 2 groups: patients of group 1 (n=18) were injected with intracoronary epinephrine 100 μg, patients of group 2 (n=22) received standard therapy without epinephrine. The groups did not differ in the main baseline clinical and anamnestic characteristics, with the exception of the predominance of men in the control group: 86.4% vs. 55.6% (p=0.03). Results. In the epinephrine group, TIMI 3 blood flow was more often achieved: 55.6% vs. 0% (p<0.01); reduction in ST elevation >50% within 1 hour after PCI: 72.2% vs. 31.8% (p=0.01). Concentrations of troponin I 12-24 h after PCI were significantly lower in the epinephrine group than in the control group: 15.2 (6;25) ng/ml vs. 25 (10;40) ng/ml (p=0.03). No life-threatening hemodynamic disorders or cardiac arrhythmias were recorded after the administration of epinephrine. No statistically significant differences were found in cardiac ultrasound data and MACE (Major Adverse Cardiovascular Events) during 30 days of follow-up.Conclusions. Intracoronary epinephrine 100 μg in STEMI patients with refractory no-reflow phenomenon during PCI is a safe and effective method for improving the blood flow in the infarct-related coronary artery. The prevalence of refractory no-reflow phenomenon among STEMI patients in our study reached 4.6%.