Objective: to conduct comparative analysis of the expression levels of microRNA-101, microRNA-142, microRNA- 27, microRNA-339 and microRNA-424 in patients with severe chronic heart failure and in heart recipients in the early and long-term period following heart transplantation and to determine the association with acute transplant rejection. Materials and methods. The study included 46 heart recipients, among whom were 36 men (78.3%); the average age of the recipients was 47.7 ± 10.8 (16 to 67) years, and 12 patients with end-stage chronic heart failure, among whom were 8 men (66.7%); the average age of the patients was 46.1 ± 6.4 (37 to 64) years. The control group consisted of 12 healthy individuals, not significantly different by gender and age. microRNA expression levels in blood plasma were determined through quantitative polymerase chain reaction (Q-PCR). Transplant rejection was verified via morphological analysis of endomyocardial biopsy specimens. Results. Blood plasma of patients with end-stage chronic heart failure had significantly higher expression rates of microRNA-101, microRNA-27, microRNA-339 and microRNA-424 than in healthy individuals (p < 0.02). In the early stages following transplantation, the expression levels of microRNA-101 and microRNA-27 in heart recipients were significantly lower than in patients with severe chronic heart failure (p < 0.003). A year or more after transplantation, there were no significant differences in the expression levels of microRNA-101, microRNA- 142, and microRNA-339 in heart recipients and in healthy individuals. In recipients with acute rejection, the expression levels of microRNA-101 and microRNA-27 significantly differed from that of recipients without signs of rejection (p = 0.04 and p = 0.03, respectively). Conclusion. The obtained data on changes in the expression levels of microRNA-101 and microRNA-27 in heart recipients with acute transplant rejection suggests possible diagnostic value of these biomarkers in determining the risk of rejection.