Heterogeneous catalysts have emerged as potential alternatives to their homogenous counterparts, since they could successfully overcome the shortcomings encountered in homogenous catalytic transesterification of tri-acyl glycerides. In the present study, application of pure as well as doped CaO derived from waste chicken egg shells was studied for conversion of oil into biodiesel. Waste eggshells were calcined at 900 degrees C to get CaO which was then incorporated into transition metals by incipient wet impregnation method. The catalyst prepared has been characterized by Scanning electron microscope (SEM), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) techniques. The basicity and surface area of catalysts were ascertained in order to figure out the catalytic activity. The conversion of oil to Fatty acid methyl esters (FAME) has been confirmed by Thin-layer chromatography (TLC) and the percentage yield of eucalyptus biodiesel was verified by Gas chromatography with Flame ionization detector (GC-FID). The catalytic property of these mixed metal oxides has been studied in trans-esterification of Eucalyptus Oil. Zn-CaO (waste egg shell) was observed to be the most promising catalyst providing with appreciable yield of bio-diesel (FAME) among all the three catalysts. Transesterification was carried out at different process variables to optimize the best reaction conditions. Employing waste chicken egg shell derived CaO doped with transition metals (Zn, Cu) as catalyst puts forward the economic and efficient scheme for trans-esterification of Eucalyptus oil for biodiesel generation. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.