Chitin and chitosan prepared from lobster shell wastes were used as adsorbents for the removal of various dyes from aqueous solutions. It was shown that high adsorption capacities were observed for reactive dyes. The adsorption equilibrium data could be well described by Langmuir equation under the concentration range investigated (50–500 mg/L). On the basis of Langmuir adsorption capacity, chitosan obtained in this work was found to be more effective compared to chitin and a commercial chitosan.