© 2020 Elsevier Inc.Organophosphates cause increased oxidative susceptibility of erythrocytes and changes in erythrocyte deformability ability. We aim is to investigate the role of ethion (ETH) on erythrocyte deformability and to show whether vinpocetine (VIN) and carnosine (CAR) are protective against these changes. The study was performed on Sprague Dawley rats with an average weight of 220 ± 40 g and 4–5 months old. Six experimental groups were composed of 10 rats per group. Hematological parameters, erythrocyte deformability, % hemolysis, 2.3bisphosphoglycerate, and methemoglobin values were measured in blood samples taken after 10 days of drug application. Erythrocyte count, hemoglobin amount, hematocrit value, serum potassium level, and erythrocyte deformability decreased in the ETH group. Leukocyte, platelet count, methemoglobin amount, and % hemolysis rates increased in the ETH group. The values of the ETH + CAR and ETH + VIN groups were found to be closer to the control group. In organophosphate poisoning such as ETH, the deformability ability of erythrocytes exposed to constant oxidative stress is changing, and therefore their ability to deliver oxygen to tissues is negatively affected. VIN and CAR may have improve on erythrocyte deformability in this type of intoxication.