Most antidiabetic polyherbal preparations contain Trigonella foenum-graecum, Momordica charantia and Cinnamomum zeylanicum as active components. Although all ingredients are popular as antidiabetic agents, but the analytical method is not available for simultaneous estimation of marker compounds from herbal formulations due to several challenges. Hence, the HPTLC method was developed for simultaneous estimation of three active phytoconstituents viz. diosgenin, charantin and hydroxychalcone in polyherbal formulation. The stationary phase of the optimized HPTLC method is silica gel 60 GF254 and the mobile phase is chloroform: glacial acetic acid: methanol: water (4:3:2:1v/v). The Rf value of phytoconstituents charantin, diosgenin, and hydroxychalcone was found to be 0.72, 0.61 and 0.30 at detection wavelength 342 nm. According to ICH criteria, the analytical method validation was performed. All three markers showed linear and proportional responses in the 400 to 1400 ng/band range, which confirmed the markers’ linearity. Precision measurements were made at the intraday and interday levels, and the results were satisfactory and in line with the specifications. Accuracy was determined by the recovery method and %recovery was found to be in the range of 85.20 to 97.19. The validated HPTLC method was utilized to analyze the marketed Quanto Diab Forte capsule formulation containing charantin, diosgenin, and hydroxychalcone. The proposed validated analytical method was found to be simple, precise and accurate.