<p>A method for determining the concentrations of mixture components from their optical absorption spectra in the presence of Rayleigh scattering that was based on the use of the differential evolution method to minimize the root-mean-square difference between the experimental and calculated spectra was proposed. The component concentrations of a model mixture were determined from its simulated optical absorption spectrum to demonstrate the performance of the method. The model mixture included five azo dyes with significantly overlapping absorption spectra and a noticeable light scattering contribution. The influence of the absorption spectrum errors on the errors of component concentrations was evaluated. Both the multiple linear regression and differential evolution methods without light scattering gave determinations of the component concentrations agreeing within the measurement accuracy. It seemed reasonable to use the differential evolution method for spectrophotometric determination of the mixture component concentrations in the presence of light scattering.</p>