Three types of vinylsulphone dyes were measured in the effluent in thisstudy. The selected dyes were Remazol Yellow RR (monofunctional), Remazol Blue RR (homo bi-functional) and Remazol Red RR (hetero bi-functional). The extinction coefficients of these dyes were measured by creating absorbance versus concentration curves. The absorbance values were obtained by testing standard solutions of each dye in a UV–visible spectrophotometer. The dyeing process was carried out at 4 different dye concentrations (0.025 g/40 ml, 0.05 g/40 ml, 0.10 g/40 ml and 0.15 g/40 ml) on a 5-g fabric sample for each of the dyes. The post-dye liquors and post-wash liquors were tested in an UV–visible spectrophotometer, and their concentrations were calculated using the Beer–Lambert law. The contribution of these dyes to the effluent was calculated and compared, and their adsorption isotherms (Langmuir and Freundlich isotherm) were analysed.