Abstract: Herbal medicine has been used for many years by different cultures around the world for the treatment of diabetes. Salvia verticillata L. was investigated for its possible antidiabetic effect in normal and streptozotocin-induced diabetic rats. The animals were made diabetic using by streptozotocin (70 mg kg-1, i.p.). The ethanolic extract (0.05, 0.1 and 0.2 g kg-1) were administered orally. The control groups were administered saline. Oral administration of ethanolic extract of Salvia verticillata aerial parts for 14 days on the level of serum glucose, total cholesterol, triacylglycerol, urea, uric acid, creatinine, aspartate aminotransferase and alanine aminotransferase in normal and streptozotocin-induced diabetic rats were evaluated. At the end of the experiment, rats were fasted overnight and blood samples were collected. A comparison was made between the action of extract and a standard antidiabetic drug, glibenclamide. Oral administration of 0.05, 0.1 and 0.2 g kg-1 b.wt. of the ethanolic extract of Salvia verticillata aerial parts for 14 days exhibited a significant reduction in serum glucose, total cholesterol, triglycerides, urea, uric acid, creatinine, aspartate aminotransferase, alanine aminotransferase and increased plasma insulin in diabetic rats. It also prevents body weight loss in diabetic rats. The administration of extract did not change these serum parameters in normal rats. The antidiabetic effect of the extract was similar to that observed with glibenclamide. So, our study revealed the anti-diabetic potential of Salvia verticillata and this study could be helpful to develop medicinal preparations for diabetes and related symptoms.