Nowadays, no-drug treatments (medicinal plants) are novel therapeutic approaches in the treatment of diabetes. Broccoli is a plant in the cabbage family, whose large flower head is used as a vegetable. The mass of flower heads is surrounded by leaves. Broccoli was derived from cultivated leafy cole crops in the Northern Mediterranean in about the 6th century. This study aimed at assessing the effect of Broccoli leaves extract on the blood glucose and lipid profile in diabetic rats. Thirty male adult rats were randomly selected and divided into three groups as nondiabetic control; diabetic control; diabetic rats treated with hydroalcoholic extract of Broccoli leaves. In diabetic groups alloxan monohydrate (100 mg/kg) was injected intraperitoneally to develop diabetes. Then the Test group received intraperitoneal injection of hydro-alcoholic extract of Broccoli leaves (100 mg/kg). At last, glucose cholesterol, triglyceride, HDL, VLDL, LDL and insulin contents of the rats' serum sample were determined Diabetic rats treated with extract showed a significant decrease in blood glucose level (p<0.05). Furthermore compared diabetic group, in the extract-treated rats, there was a significant decrease in serum contents of total cholesterol (TC) ,LDL,VLDL and TG, but a significant increase in insulin level and HDL (p<0.05). These results show that the hydroalcoholic extract of Broccoli leaves may be effective in the treatment of diabetes. This effect can be due to the presence of flavonoides and their antioxidant features.