In this study, new pH-sensitive polymeric microparticles were obtained by the cross-linking of poly(N-vinyl caprolactam-co-maleic acid) (VCL-MAc). Their swelling in pure water was very high, but was in a large extent influenced by the pH and by the presence of cationic hydrophobic molecules. These microparticles were successfully used in the adsorption of rhodamine 6G and methylene blue from aqueous solution. The effect of different parameters such as initial pH, adsorbent dose, temperature, initial dye concentration, and contact time on their dye adsorption capacity was studied using the batch-adsorption technique. The equilibrium adsorption data were better fitted with Langmuir isotherm, compared to Freundlich model. The maximum adsorption capacities at pH = 10 were found 2012 and 1441 mg/g for rhodamine 6G and methylene blue, respectively. The kinetic experimental data were well described by the pseudo-second-order model, the rate constant k (2) increasing with the pH and the initial dye concentration. The results show that the new VCL-MAc microparticles can be effectively used in the removal of cationic dyes from waste water.