Quaternized sawdust modified with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHMAC) was evaluated for its ability to remove two reactive dyes (Reactive Blue 19 & Reactive Red 4) from aqueous solution. The adsorption capacities of Reactive Blue 19 and Reactive Red 4 on quaternized sawdust were approximately five and sixteen times higher than that of activated carbon (F-400), respectively. Moreover, adsorption on quaternized sawdust was hardly affected by salt concentration. It was also found that the degree of sawdust quaternization has a good linear relationship with the maximum adsorption capacity. This indicates that the electrostatic interaction between anionic sites in reactive dyes and quaternized cationic sites in sawdust is of primary importance in terms of the adsorption characteristics of the two reactive dyes. However, the desorption test of dyes adsorbed on quaternized sawdust showed poor performance in NaOH and NaCl solution, suggesting additional undefined binding forces.