Palladium incorporated ZnO nanoparticles were synthesized using incipient wetness impregnation method in different concentrations of Pd incorporated in ZnO nanoparticles and their effects as a photocatalyst under UV laser radiations in the removal of Escherichia coli microorganism from water were studied. A significant improvement in the rate constant of the bacterial decay process was observed and discussed on the basis of the blue shifted band gap energy of nano-ZnO due to the incorporation of palladium. The morphological study of Pd incorporated ZnO nanoparticles was carried out using Field Emission Scanning Electron Microscope and High Resolution Tunneling Electron Microscope and the grain size of the synthesized material was found to be in the 15-30 nm range. The photoluminescence spectra and the absorption spectra showed a blue shift in the band gap energy of Pd incorporated ZnO nanoparticles, which positively contributed to the enhanced photocatalytic activity. (C) 2011 Elsevier B.V. All rights reserved.