Abstract: This research was carried out to examine the effects of methanol leaf extract of U. pilulifera on some hematological and biochemical parameters in diabetic rats. Forty rats weighting 150-185 g were divided into four groups: group I treated with a vehicle (control); group II including diabetic rats treated with a vehicle; groups III and VI including diabetic rats treated with 1.0 and 2.0 g kg^-1 of the extract for 3 weeks, respectively. Rats were made diabetic by injection with a single dose of streptozotocin (70 mg kg^-1, i.p). At the end of the experimental period, rats were killed and blood samples were taken for biological analysis. The blood glucose level, Erythrocyte Sedimentation Rats (ESR), Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), urea and creatinine levels significantly increased in diabetic rats as compared to control. By contrast, significant reduction of the erythrocyte and leukocytes counts and Pack Cell Volume (PCV), Thyroxine (T₄) and Triiodothyronine (T₃) and Thyroid Stimulating Hormone (TSH) levels in diabetic group were also noticed in diabetic rats as compared to control. Treatment of diabetic rats with this extract caused a significant decrease in blood glucose levels, ESR, urea and creatinine, whereas ALT and AST slightly lowered. In addition, in diabetic treated groups, the erythrocyte and leukocyte counts and PCV, T₃, T₄ and TSH values significantly increased, whereas the leukocyte count slightly increased. We can concluded that U. pilulifera extract improves the diabetic status in terms of blood sugar and alleviates the diabetes-induced disturbances of some hematological and biochemical parameters of rats.