The analysis indicated that the formation of a complete monolayer was not achieved for adsorption of any reactive dyes on the anion exchanger and the maximum monolayer capacity values ranged from 1.36 to 1.66mmol/mg for C.I. Reactive Black 5, from 2.27 to 2.65mmol/mg for C.I. Reactive Red 2 and from 0.47 to 0.71mmol/mg for C.I. Reactive Red 120 at the temperature of 298–318 K