The present clinical trial was designed to evaluate the safety and efficacy of a polyherbal formulation (PHF) consisted of Allium sativum, Aloe vera, Nigella sativa, Plantago psyllium, Silybum marianum and Trigonella foenum-graecum for controlling dyslipidemia and hyperglycemia in patients with advanced-stage of type-2 diabetes. An open-label phase I trial was carried out on 30 patients who had hyperlipidemia and hyperglycemia before the beginning of the trial in spite of receiving statins and oral hypoglycemic drugs. Patients were given one PHF sachet two times daily for 40 consecutive days. All subjects also continuously received their statins and oral hypoglycemic agents. Clinical assessments and laboratory findings were evaluated before starting treatment and at day 40. Treatment with PHF had no significant effects on serum biochemical parameters related to liver and kidney functions, on hematological parameters related to erythrocytes, leukocytes, and platelets, and on body weight and blood pressure. After consumption of PHF, 2 patients complained of mild nausea, and 2 patients reported diarrhea. PHF significantly decreased fasting blood glucose and HbA1c from 162±40mg/dL to 146±37mg/dL and from 8.4±1.5% to 7.7±1.1%, respectively. Also, it significantly decreased the level of LDL from 138±25mg/dL to 108±36mg/dL, and the level of triglycerides from 203±47mg/dL to 166±58mg/dL. In conclusion, the present results demonstrated that the PHF was safe and efficacious in lowering the levels of blood glucose and serum lipids in patients with advanced-stage of type-2 diabetes.