The effect of interesterification on oxidative stability of cottonseed, palm and soybean oils stored under oven conditions at 45, 60 and 75C was evaluated by measuring the peroxide values (PV), anisidine values (AV) and Totox values at different time intervals. Fatty acid composition and tocopherol contents of oil samples were determined before and after interesterification. Interesterification reduced the tocopherol content of oils. The interesterified oils showed lower PV and AV than their non-interesterified counterparts in all temperatures and time intervals. The primary and secondary oxidation reaction constants and reaction orders were investigated as a function of the reaction temperature. The interesterified oils showed lower reaction rate constants than the non-interesterified samples. Based on PV, AV and reaction rate constants, the oxidative stability of interesterified oils were higher than their non-interesterified counterparts.