In this study, it was aimed to investigate the effects of highbush cranberry ( Viburnum opulus , GILA) fruit extract on blood glucose levels and kidney tissue homogenates of diabetes-modeled rats by injection of Streptozotocin (STZ). Blood glucose levels of rats were measured in tail blood using a glucose meter. Glucose determination was done 48 hours after STZ injection. For this, 32 Wistar albino rats were employed. The rats were divided into 4 groups; Control, STZ, STZ+GILA, and GILA with containing 8 animals each. After 12 weeks, they were sacrificed. During the study periods, blood glucose levels were measured periodically and kidney tissue parameters were measured in their homogenates after sacrificing the rats. The measured parameters were Glutathion (GSH), Malondialdehyde (MDA), and Total Antioxidant Status (TAS). The results obtained from the study were analyzed by using SPSS for Windows software, and p<0.05 was assigned as statistically significant value. The findings of the study showed that GILA consumption could help diabetic people to prevent possible nephropathy due to its potent antioxidant features.