This paper proposes a hybrid chemometric method named DOSC-WPT-PLS, which is based on partial least squares (PLS) regression combined with direct orthogonal signal correction (DOSC) and wavelet packet transform (WPT) as pre-processing tools for the simultaneous spectrophotometric kinetic determination of Mn (II), Ag (I) and Fe (III). This method combined with kinetic approach is used for the first time and no past reference has been found for this determination. The improved PLS regression algorithm was developed by adding a preprocessor based on DOSC and WPT to enhance the prediction ability. The kinetic chemometric approach that combines kinetic-catalytic method with DOSC-WPTPLS does not require a detailed kinetic model of the chemical system to obtain the order of reaction and rate constants. The relative standard errors of prediction (RSEP) obtained for all components using DOSC-WPT-PLS, WPTPLS and PLS were compared for evaluating their predictive capability. Results obtained from the DOSC-WPT-PLS method were significantly better, and proved that it outperformed the WPTPLS and PLS methods.