Objective: to evaluate the frequency and identify risk factors for the development of stent restenosis in patients with acute coronary syndrome (ACS) after percutaneous transluminal coronary angioplasty Material and methods. Retrospective analysis of 665 case histories of patients with acute coronary syndrome who were hospitalized from January to November 2023 was performed at the 1st stage of the study. At the second stage we analyzed the risk factors of in-stent restenosis development based on clinical and laboratory data in the compared groups of patients: group 1 (n=62) and group 2 (n=55). Results. Stent restenosis was detected in 62 patients out of 665 (9.3%). The risk of in-stent restenosis was significantly influenced by concomitant type 2 diabetes mellitus (OR 1.6 (1.2-2.3); p=0.007), IBS duration of more than 10 months (OR 2.24 (1.7-3.0); p=0.001) and stenting with a holometallic stent (OR 1.8 (0.9-3.4); p=0.049). Conclusion. The incidence of stent restenosis after stenting for ACS is 9.3%. Concomitant diabetes mellitus and duration of the underlying disease of 10 months are risk factors for early restenosis.