Cross-linked chitosan(C)/marble powder (M) composites with different weight ratio percentage (C100M0, C70M30, C50M50, and C30M70) were prepared from marble powder and chitosan and cross-linked using glutaraldehyde. The morphology and the surface area of the chitosan/marble powder composites were also characterized with a scanning electron microscope (SEM) and Micromeritics (ASAP 2020) BET (Brunauer, Emmett and Teller) instrument, respectively. To evaluate the adsorption behaviour of the chitosan/marble powder composites, 0.1 g adsorbent was added into 50 mL Diamozol Blue BRF %150 (C.I. Reactive Blue 221) solution with fixed concentrations (60 mg/L). At equilibrium, the adsorption capacity of C100M0, C70M30 and C50M50 for Dimozol Blue was about 27 mg/g and significantly greater than that of C30M70. C50M50 composite was more economical than C100M0 and C70M30 due to the higher marble powder content, and hence was selected as an adsorbent for the removal of Dimozol Blue from aqueous solution. The adsorption kinetics and equilibrium isotherms of Dimozol Blue onto the chitosan/marble powder composites from aqueous solution were investigated. The studies revealed that Dimozol Blue dye adsorption was described well by the pseudo-second-order and Freundlich isotherm models. The results of this study indicated the applicability of the chitosan/marble powder composites for removing industrial dyes from aqueous solution.