Heterogeneous nanocatalyst has become the choice of researchers for better transesterification of vegetable oils to biodiesel. In the present study, transesterification reaction was optimized and kinetics was studied for biodiesel production from neem oil using CZO nanocatalyst. The highly porous and non-uniform surface of the CZO nanocatalyst was confirmed by AFM analysis, which leads to the aggregation of CZO nanoparticles in the form of multi layered nanostructures. The 97.18% biodiesel yield was obtained in 60 min reaction time at 55 degrees C using 10% (w/w) CZO nanocatalyst and 1:10 (v:v) oil:methanol ratio. Biodiesel yield of 73.95% was obtained using recycled nanocatalyst in sixth cycle. The obtained biodiesel was confirmed using GC-MS and H-1 NMR analysis. Reaction kinetic models were tested on biodiesel production, first order kinetic model was found fit with experimental data (R-2 = 0.9452). The activation energy of 233.88 kJ/mol was required for transesterification of neem oil into biodiesel using CZO nanocatalyst. (C) 2015 Elsevier Ltd. All rights reserved.