A solid-phase extraction method, based on the adsorption onto Diaion HP-20 resin, was developed for simultaneous spectrophotometric determination of Lanaset Blue 2R and Lanaset Yellow 28 dyes which are most together hazardous textile dyes in wastewater. Concentrations of the dyes were determined using UV-visible spectrophotometer at 625 and 438 nm for LB-2R and LY-28, respectively. The developed method was also applied to water samples. In dying process water, 572 +/- 15 mu g/mL and 396 +/- 6 mu g/mL of LB-2R and LY-28 dyes were determined. In addition, adsorption isotherms of the method, point of zero charge and surface micrographs of the resin were investigated. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.