The present study aims at the development and characterization of zinc oxide (ZnO) nanoparticles as a carrier for various anti-cancerous drugs viz. 5-Fluorouracil (5-FU), Doxorubicin (DOX) and Daunorubicin (DNR). ZnO nanoparticles were prepared by standard precipitation method. The measurement of optical band gap using UV-Visible Diffuse Reflectance Spectroscopy (DRS) analysis reveals the lowering of ZnO band gap after the drug loading. Crystallite size of free and drug loaded ZnO nanoparticles were determined using X-ray Diffraction (XRD) analysis. The crystallite size of ZnO nanoparticles increases after the drug loading. Both the techniques confirm the adsorption of drug molecules on ZnO surface. © 2019 American Institute of Physics Inc.. All rights reserved.