Chitosan (CS) can be used as adsorbent in the treatment of effluents from the textile industry, especially for negatively charged dyes, due to its cationic polyelectrolyte nature. In this work, the adsorption of a model dye, methyl orange, xylenol orange on hollow CS microsphere is analyzed. Adsorption of methyl orange, xylenol orange onto cross-linked CS is realized by means of analysis of pH influence, agitation time, and initial concentration of the dye. The results obtained from the experiment shows that the adsorption capacities of the two dye-hollow CS microsphere systems are higher than those stated in other literature using CS particles. The difference in the degree of adsorption may also be attributed to the size and chemical structure of the dye molecule. The results have demonstrated that monovalent and smaller dye molecular sizes have superior capacities due to the increase in dye/CS surface ratio in the system and deeper penetration of dye molecules into the internal pore structure of hollow CS microsphere. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2065-2071, 2011