This paper proposes a simple approach for sensing of dimethyl disulfide (DMDS) using reduced graphene oxide (RGO) nanosheets and chitosan (CS) modified glassy carbon (GC) electrode. Graphene oxide was synthesized chemically by employing a modified Hummer method and characterized by UV-Vis, FT-IR and Raman spectroscopies and also X-ray diffraction (XRD). The RGO nanosheets and CS layer were electrodeposited successively onto the surface of a glassy carbon electrode in two separate steps. The morphology and electrochemical properties of the CS/RGO film have been characterized by Transition Electron Microscopy (TEM) and cyclic voltammetry (CV). The effects of relevant parameters such as the electrodeposition techniques, the amounts of the graphene oxide (GO) and the chitosan, and also the pH of the solution have been investigated and optimized. Analytical performance of the CS/RGO/GC modified electrode for determination of DMDS has been evaluated. Under optimized operating conditions, a concentration linear range of 1- 500 mg L-1 with a detection limit of 0.9 mg L-1 of DMDS have been obtained. Also, the RSD of the method was achieved to be 2.1%. Furthermore, the voltammetric technique employed to determination of DMDS in various natural waters using the CS/RGO/GC modified electrode (C) 2014 Elsevier Ltd. All rights reserved.