In this paper, the effects of two factors including pH of the reaction mixture and temperature in heat treatment involved in synthesis of ZnWO4 nanoparticles are represented. ZnWO4 nanocrytsallites were obtained from zinc nitrate and sodium tungtsate. The different conditions of pH and calcination temperature were provided in order to scrutinize their impact on the structural and morphological changes. The obtained powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Nanocrystalline ZnWO4 powder synthesized at pH = 9 and calcined at 600oC showed an excitation band at 295 nm and a broad emission band at 477 nm.