The aim of this article is to prepare Tungsten oxide (WO3) nanoparticle along with manganese (3 and 10 wt%) by Microwave irradiation method. The synthesized Mn doped WO3 materials were characterized by XRD, FTIR, TEM, UV-DRS and photoluminescence studies. XRD reveals that Mn doped WO3 crystallizes in monoclinic structure. FTIR confirms tungsten and oxygen presence. TEM shows spherical nanoparticles with particle size 35–50 nm. UV-DRS confirms band gap reduction and a red shift in absorption edge. Defects and oxygen deficiencies were analyzed through photoluminescence. Photocatalytic activity was evaluated using methylene blue degradation under visible light, showing Mn doped WO3 has superior activity compared to pure WO3. © 2017 Elsevier B.V., All rights reserved.