A simple microwave assisted technique has been successfully developed to synthesize ZnWO4 nanoparticles. The X-ray diffraction results indicated that the synthesized nanoparticles exhibited only wolframite structure. Structural, morphological and optical properties of ZnWO4 nanoparticles have been analyzed by XRD, SEM, TEM EDAX, UV-vis and FT-IR spectral measurements. The transmission electron microscopy (TEM) image revealed that particle size of ZnWO4 nanoparticles was found to be 10 nm, the band-gap of ZnWO4 nanoparticles was found to be 3.4 eV. The photocatalytic activities for aqueous Rhodamine B and Methylene Blue samples were investigated and observed that ZnWO4 nanoparticles exhibited highly enhanced photocatalytic activity towards RhB than MB. (C) 2012 Elsevier Ltd. All rights reserved.