Double divisor-ratio spectra derivative method based on the spectrophotometric data was developed for the simultaneous analysis of a ternary mixture containing quercetin, berberine HCl and curcumin in phosphate buffer pH-7.4. This method is based on the use of the derivative of the ratio spectrum obtained by dividing the absorption spectrum of the ternary mixture by a standard spectrum of a mixture of two of the three compounds in the title mixture. The concentrations of three phytoconstituents in their mixture were determined by using their respective calibration graphs which are obtained by measuring the amplitude at either the maximum or minimum wavelengths selected. The selected wavelengths for determination of quercetin, berberine HCl and curcumin are 355.11 nm, 264.68 nm, and 399.15 nm, respectively. The mean % recoveries were found to be in the range of 98.66 - 99.23%, 99.67 - 100.56 % and 98.28 - 99.54 % for quercetin, berberine HCl and curcumin, respectively. The method was successfully applied to analyze quercetin, berberine HCl and curcumin in polyherbal gel formulation with no interference from excipients as indicated by the recovery study. All validation parameters were well within the acceptable range.