A multicomponent analysis method is proposed for the determination of chlorophenols by diode array derivative spectrophotometry. The method is based on formation of ion-pairs with tetrabutylammonium as counterion and extraction in chloroform at pH 9.1. Quantitative determinations (within the 2-20 mg/l. concentration range) of two-, three- and four-component mixtures were possible, using the first derivative spectra and a least-squares computer programme.