In this paper zinc stannate (ZnSnO 3 ) nanoparticles was synthesized by a chemical precipitation method. The synthesized samples were characterized using X-ray powder diffraction (XRD), Differential scanning calorimetry (DSC) and UV-Visible absorption spectroscopy. Sensing material was made as pellet by hydraulic press machine under uniform pressure of 616 MPa. Then the material was annealed at 600˚C. Surface morphologies of the samples were analyzed using Scanning electron microscopy (SEM) for pellet of different weight ratio annealed at 600˚C. The XRD pattern indicates that ZnSnO 3 has a perovskite phase with an orthorhombic structure having minimum crystallite size 4 nm. Further, humidity sensing investigations of these sensing materials were done. Our result indicate that ZnSnO 3 in form of pellet annealed at 600˚C for 1:4 weight ratio was most sensitive of humidity in comparison to pure SnO 2 under same conditions. Maximum sensitivity of the sample was 3 GΩ/% RH which is better in comparison to pure SnO 2 . The results were reproducible up to ± 77% after 2 months of observations.