Barium zirconate was synthesized by co-precipitation method and its feasibility as a heterogeneous catalyst for production of biodiesel (fatty acid methyl ester) was assessed. Fatty acid methyl ester (FAME) was synthesized through transesterification of karanja oil with methanol. Synthesized barium zirconate was characterized by Thermogravimetric analysis (TGA), Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometry (XRD), Energy dispersive X-ray spectroscopy (EDS), and Scanning Electron Microscope (SEM). Specific surface area and basicity of the catalyst were also deliberated. Catalyst characterization indicated formation of single phase of barium zirconate which was capable of catalyzing the transesterification of esterified karanja oil with methanol. Feedstock was characterized by Gas Chromatography Mass Spectrometry (GC-MS). Reaction conditions such as molar ratio (oil:methanol), catalyst concentration, temperature, time, stirring speed and catalyst reusability were optimized. Calcination temperature and time significantly affected the catalytic activity of the catalyst because of variation in availability of basic sites. FAME conversion of 98.79 0.5% was obtained at catalyst concentration of 1.0 wt%, 1:27 M ratio (oil:methanol), 65 degrees C for a 3 h contact time. The catalyst could be reused up to nine cycles and >65% fatty acid methyl ester conversion was sustained at ninth cycle. Glycerol obtained as a by-product was purified and analyzed by FTIR. Effect of catalyst on various feedstock at the same reaction conditions were studied. Physicochemical properties of karanja oil and respective methyl ester in comparison with petro diesel were also deliberated as per ASTM standards. (C) 2016 Published by Elsevier Ltd.