The polyherbal formulation containing Allium sativum L., Terminalia bellirica (Gaertn.) Roxb., Curcuma aeruginosa Roxb., and Amomum compactum Sol ex. Maton has been used for hypertension treatment empirically. Our previous study showed its blood pressure-lowering effect on a rat model of hypertension. However, toxicity data were not available for this polyherbal formulation. This study is aimed at evaluating the acute and subchronic oral toxicity of the polyherbal formulation in rats. The acute toxicity study was conducted on 6 female Wistar rats using the fixed-dose method for the treatment group and 5 female Wistar rats for the control. The single dose of 2,000 mg/kg of the polyherbal formulation was given orally. There were no significant toxic effects and no death observed until the end of the study, and it was showed that the lethal dose 50% (LD50) of the polyherbal formulation was estimated to be more than 2,000 mg/kg. The macroscopic and microscopic examination of vital organs showed no symptoms of toxicity. At the subchronic toxicity study, the polyherbal formulation with 3 dose variations of 252 mg/kg, 1,008 mg/kg, and 4,032 mg/kg was administered for 91 days orally. The lowest dose of 252 mg/kg is equivalent to the daily recommended dose for a human. There were no significant toxic effects observed at all doses on physical sign and symptoms, weight gain, food intake, hematological parameters, biochemical parameters, and macroscopic and microscopic examination of organs. These findings showed that the short- and long-term oral administration of the polyherbal formulation is safe to use within its dose recommendation.