Diabetes mellitus (DM) is caused by hyperglycemia, resulting from defective insulin secretion or function. It is widely believed that the antioxidant micronutrients obtained from plants afford significant protection against diseases like diabetes mellitus. Present study was aimed to examine the effects of Persian shallot (Allium hirtifolium Boiss) on FBS, HbA1c, insulin, triiodothyronine (T3) and thyroxine (T4) levels in type 1 diabetic rats. Thirty two male Wistar rats were divided into 4 groups of 8. The diabetic groups received 100 and 200 mg/kg Persian shallot extract, diabetic control and normal control received %0.9 saline for 30 days. At the end of treatments, fasting blood specimens were collected. The levels of FBS, HbA1c, insulin, T3 and T4 were measured. Our findings indicated that hydroalcoholic extract of Persian shallot significantly decreased serum levels of FBS and HbA1c in treated groups (in a dose dependent manner) (p<0.05). The serum levels of insulin and T3 slightly increased by Persian shallot but the T4 serum level was declined. These beneficial effects of Persian shallot extracts in diabetic rats could probably be due to the antioxidant capacity of its phenolic and diallyl disulfide content.