Abstract: ZnS thin films on glass substrate have been prepared by home built spray pyrolysis technique at 220, 250 and 280°C. Aqueous solution of 50 mL containing zinc acetate dihydrate and thiourea salts of 1:1 M is sprayed as fine mist at a pressure of 2 kg cm-2 with flow rate of 3 mL min-1 on preheated glass substrate. Film obtained at 220°C found to be amorphous and polycrystalline at 250 and 280°C with preferential orientation along (111) plane. X-ray line broadening technique is utilized to determine the grain size and microstrain of the ZnS film. Compositional studies indicate the presence of oxygen for the film prepared at 250°C. The effect of substrate temperature on crystalline structure, surface morphology and composition were analyzed and reported.