Background: The microrheological disorders of red blood cells in obesity is often missed by the researchers. This study aimed to report an experimental investigation on laboratory animals with developed obesity and to find out the effect of meldonium on the erythrocytes. Methods: A total of 95 healthy male-rats of Vistar line were taken into the investigation, 29 animals had experienced no impacts and allocated as the control group, while 64 rats which had developed obesity induced by a cardioangionefopathogenic semisynthetic diet into the obesity group. These rats were casually divided into an experimental (34 rats) group and the control group (30 rats). The rats of the experimental group in the next ten days were intragastrically injected with meldonium for 80 mg/kg. The biochemical, hematological and statistical methods of investigation were used in this study. Results: During the formation of obesity and the use of meldonium, the body weight of the rats were gradually decreased to the normal level. On the obese rat’s group receiving meldonium, the content of the lipids peroxidation products in erythrocytes progressively decreased. and reached the level of the healthy control rats group. Moreover, there was a decrease in the number of erythrocytes-discocytes accompanied by an increase in the reversible and irreversible changes. These values were returned to the level of the healthy control rats group at the end of the observation. This pattern was observed in the total number of erythrocytes aggregate and free erythrocytes. Conclusion: The application of meldonium eliminates the existing erythrocytes abnormal microrheological features in the rats with recently developed obesity. © 2020, Sanglah General Hospital. All rights reserved.