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In the present studies the adsorption efficiency of peach nut shells for the removal of endosulfan from aqueous solutions has been investigated. The adsorption of endosulfan has been studied as a function of contact time, concentration and temperature. Maximum adsorption (95 ± 1%) was achieved for 0.24 × 10−4 mol dm−3 of endosulfan solution, using 0.1 g of adsorbent in 20 ml of solution for 30 min agitation time at pH 6. The Freundlich and Langmuir isotherms fit the equilibrium data satisfactory and their constants, adsorption intensity 1/n (0.36), multilayer adsorption capacity Cm 6.5 ± 0.26 mmol g−1, and monolayer adsorption capacity Q 0.27 ± 0.03 mmol g−1, have been evaluated. Thermodynamics parameters namely change in enthalpy ∆H, Gibbs free energy ∆G and entropy ∆S, were calculated. The negative values of ∆G and positive value of ∆H indicate that the adsorption process is spontaneous and endothermic in nature and positive value of entropy ∆S confirms the possibility of the favorable adsorption. The developed adsorption method has been employed to surface water samples.