In the production of nanoparticles, the bio-reduction properties of plant extracts are acknowledged worldwide to reduce the harmful effects of physical and chemical methods of synthesis of nano-scale metal particles. The present study states a green approach for the synthesis of zinc oxide nanoparticles employing aqueous extracts of leaf, stem, root and inflorescence of Tridax procumbens. Zinc nitrate hexahydrate was used as precursor. Various parameters such as temperature, volume of precursor and reducing agents were optimized for maximal synthesis of zinc oxide nanoparticles. The synthesized nanoparticles in aqueous solutions were further confirmed by characterizing the reaction mixtures using the UV–visible spectroscopy. Leaf, root and inflorescence reaction mixtures presented strong absorption peak at 302 nm and the stem reaction mixture resulted at 300 nm. The nanoparticles were observed to be stable after 2 months. The present study reports that the whole plant Tridax procumbens. could be used in the synthesis of potential ZnO nanoparticles.