© 2022, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.Erythrocyte aggregation is associated with a series of physio-pathological processes in body and according to this, current study was designed to examine how the thymoquinone (TQ) and a ggregation kinetics relation changes when the aggregation properties of erythrocyte suspensions are intervened using different approaches, such as changing the suspension environment or erythrocyte surface properties. Blood samples from 40 male Wistar albino rats (three months old weighing 250-300 g) were randomly divided into four groups, as 1) whole blood (control), 2) 1/2 dilution (plasma was diluted with PBS), 3) dextran 500 (1% dextran 500 was dissolved in plasma) and 4) glutaraldehyde. Blood samples were taken from abdominal aorta under anesthesia. The erythrocyte suspensions were incubated at 37°C for one hour in the absence or presence of TQ, with a final concentration of 1 mg/ml. Then, the electrical properties of erythrocyte suspensions were recorded, and the electrical capacitance was monitored using an inductance, capacitance, and resistance meter (LCR meter) at 100 kHz. It was found that TQ incubation decreased the aggregation index in control and dextran groups while increased it in 1/2 dilution and GA groups. It was also found that TQ incubation increased the time constant in whole blood and dextran while decreased it in 1/2 dilution and GA. The TQ can normalize the altered erythrocyte aggregation responses in both ways that is, it decreases the increased aggregation or increases the decreased aggregation. Therefore, it may have very critical role in rouleaux formation-induced circulatory disorders.