The use of orange peel as low-cost and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This paper concerns with the removal of Blue 56 from aqueous solutions by orange peel. The effects of pH, initial concentration, adsorbent dosage, and particle size of adsorbent, temperature and also isotherm data analysis and adsorption kinetics were investigated. A maximum removal of 96.76% was obtained at pH 2.5 for an adsorbent dose of 0.2 mg. Rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R2=0.99). The maximumadsorption capacity obtained from Langmuir equation was9.69 (mgg-1).</div