In this study, the adsorption equilibrium of Victoria blue (VB) dye by alkali activated crab shell (AACS) was studied using batch process. The factors affecting the adsorption process, including contact time, pH, initial dye concentration, particle size, adsorbent dosage and temperature, were investigated. The models of Langmuir, Freundlich, and Temkin isotherms were used for analyze equilibrium data. The Langmuir isotherm model was found to fit the best, and the maximum adsorption capacity was 8.6 mg/g at 35°C. Thermodynamic parameters, such as ΔH, ΔG, and ΔS were calculated. Negative values of ΔG indicated that the overall adsorption was spontaneous. The characterization of adsorbent surface by FTIR confirmed that the AACS can adsorb VB dye from its solutions. Experimental results showed that the adsorption capacity increased with temperature and the AACS was an effective adsorbent for removing VB dye.