A novel CaO based catalyst, CaO-Ca12Al14O33 binary complex has been synthesized for the production of biodiesel from vegetable oils. The catalyst has been prepared on the basis of integration of CaO, as solid reactant, with a composite metal oxide, Ca12Al14O33. A non-traditional oilseed, Argemone mexicana was examined in detail as a reliable and economical bioresource for biodiesel production. The oil was extracted from the seeds and was transesterified with methanol, using a CaO-Ca12Al14O33 catalyst vis-A -vis with a conventional homogeneous sodium methoxide catalyst. In addition to providing a trouble free work-up of the reaction mixture, the novel catalyst could also be reused up to five cycles, without any major loss of its catalytic activity. Good catalytic activity of the developed catalyst has also been found in transesterification of two others non-edible oils viz. Jatropha curcas and Guizotia abyssinica. The fuel properties of the synthesized methyl ester of A. mexicana oil have been studied and found to meet the ASTM D-6751 specification of biodiesel, except for the oxidation stability and Conradson Carbon Residue properties.