The reaction orders with respect to the reactants were determined for the reaction of canola oil with methanol catalyzed by KOH/MgO. The method of initial rates was used to determine the reaction rate. The experiments were carried out with different initial concentrations of methanol and canola oil. A very good correlation was found between the experimental and calculated reaction rates using the proposed equation. The reaction rate equations derived from Eley-Rideal and Langmuir-Hinshelwood mechanisms were discussed. As a result, the orders of reaction respect to both oil and methanol are concordant with the suggestion that the reaction takes place both homogeneously and heterogeneously. (C) 2012 Elsevier B.V. All rights reserved.