Background: Hyperuricemia causes gout syndrome, which can manifest as hemorheological damage. However, hemorheological properties have not been well characterized in asymptomatic conditions. Aims: The present study was aimed to investigate the hemorheological changes in rats with asymptomatic hyperuricemia. Methods and Materials: The rat model was established by intraperitoneal injection of 250 mg/(kg center dot d) oxonate acid for 8 weeks. In one group of rats, 70 mg/(kg center dot d) allopurinol was also administrated for the latter 4 weeks. Control rats were administered CMC-Na solution and water. Results: Hyperuricemic rats had higher blood viscosity than control rats did. Moreover, their erythrocytes had reduced deformation index, orientation index, surface charges, and osmotic fragility. Treatment with allopurinol decreased the blood uric acid amounts and improved the hemorheological parameters. Conclusions: Our study suggests that there is deterioration in the hemorheology of hyperuricemic rats and that allopurinol can play a protective role on the deterioration. Therefore, hemorheology can be used as a diagnostic tool in asymptomatic hyperuricemia.