Backgrounds and Aims: Securigera securidaca (L.) seeds are used by traditional herbalists for the treatment of diabetes in several parts of Iran. Clinical investigation of its efficacy and its toxicity in diabetic patients is of importance. Methods: A 2-month randomized double blind clinical trial was conducted in 70 type II diabetic patients in two well – matched groups. One group (n=35) received 500 mg Securigera securidaca (L.) seeds capsule 3 times a day plus standard therapy, while the control group (n=35) received placebo plus standard therapy. The patients were visited monthly and glycosylated hemoglobin (HbA1c), fasting blood glucose, total cholesterol, LDL and HDL, triglyceride, SGOT, SGPT, ALK, BUN, serum creatinine levels were determined at the beginning and the end of the study after two months. Results: There was no significant change in HbA1c and fasting blood glucose level in Securigera securidaca (L.) seeds treated patients after two months as compared to beginning of the treatment and also as compare to placebo group. Serum lipid level also did not change significantly. The liver enzyme level and creatinine level in blood did not change significantly in Securigera securidaca (L.) seeds treated patients. No side effect was observed in any of patients in both of the groups. Conclusion: The results show that the Securigera securidaca (L.) seeds treatment with known antidiabetic property in traditional herbal therapy has no beneficial effect on improving glycemic profile in type II diabetic patients. The use of this herbal medicine in the dose of 1500mg in 3 divided dose showed no gasterointestinal symptom as well as liver and kidney abnormality during two months therapy. The long term efficacy and toxicity of this herbal medicine in higher dosage may be investigated in large multi center clinical study.