Noble metal/semiconductor oxide nanocomposites have considerable interest on degradation of pollutants from textile wastewaters. Ag/ZnO, as one of the noble metal/semiconductor oxide nanocomposite, is highly efficient catalyst in textile pollutant degradation that allows irradiation wavelength towards visible light region. Ultrasonic spray pyrolysis method was used to produce spherical, homogenously distributed and submicron Ag/ZnO nanocomposite particles in one step. A water leach solution (0.05-0.2 M, Ag+:Zn2+ = 1: 1) is carried by non-cost air into the reaction furnace (T = 700 degrees C, 800 degrees C and 900 degrees C). UV-A illumination of Methylene Blue (MB) with the presence of Ag/ZnO nanocatalysts after 60 min results up to 40% MB decolorization, 9 x 10 (3) min (1) decolorization rate constant. (C) 2013 Elsevier B.V. All rights reserved.