Indium doped ZnO thin films have been prepared on heated Coming 7059 glass by the pyrosol spray method. It was found that indium doping has an important role in grain growth at high substrate temperature. Indium also was used to improve the electrical properties, acting as an N type dopant, and we obtained highly conductive ZnO:In thin films with a resistivity of 3.0 x 10(-3) Ohm cm. At substrate temperatures from 325 degrees C to 475 degrees C, the deposited ZnO:In thin films have clear hexagonal crystallites and, therefore, a highly textured surface showing optical haze phenomena due to the crystallites. The haze ratio of ZnO:In thin films can be controlled from 10% to 50% at the wavelength of 550 nm by varying the substrate temperature from 375 degrees C to 475 degrees C.