The nanocomposite of Zeolite-X/Reduced graphene oxide/Polypyrrole was successfully synthesized and characterized by Fourier Transform-Infrared spectroscopy (FTIR), Powder X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermo-gravimetric analysis (TGA) for their nature, morphology and thermal stability. The gas sensing studies for the carbon monoxide detection was carried out at the concentrations ranging from 5 ppm to 1000 ppm. The effect of parameters viz. zeolite content, cyclic interval, CO concentration on the response of the nanocomposite towards CO were investigated. A lower value of response time for Na-X/rGO/PPy nanocomposite was found as compared to polypyrrole and Na-X/Polypyrrole composite which can be attributed due to the incorporation of high surface area constituents viz. zeolite and rGO in the Na-X/rGO/PPy nanocomposite. In addition, a lower value of recovery time of Na-X/rGO/PPy was found since rGO forms a layer inside and outside the Zeolite which prevents the permanent association of the CO with the Na ion of Na-Zeolite. The sensitivity value of the Na-X/rGO/PPy nanocomposite increased as the zeolite content was increased. This increase in the response by increasing the zeolite content is attributed due to the increase in the surface area of the composite. (C) 2018 Elsevier B.V. All rights reserved.