The high energy demand in the industrial world, as much in the domestic sector and the derived problems of the widespread use of fossil fuels, make increasingly necessary the development of renewable energy sources. Recent development in gene segment transfer and modification techniques suggest an alternative route for the development of diesel fuel from plant sources, especially non-edible oil seeds. In this work the transformation process of jatropha and karanja oil in order to obtain biodiesel by means of transesterification, as prepared in the laboratory is discussed.