Samples of rapeseed oils stored at room conditions were used for determination of peroxides values (PV) by iodometric titration and for thermoanalytical parameters (t(ON) and t(max)) determined with a pressure differential scanning calorimeter when used in the isothermal mode. The assessment of oxidative stabilities and the anticipation of the oxidative fate of oils based on a single PV or on t(ON) and t(max) determination is rather uncertain. The linear correlation of t(ON) and t(max) vs. PVs makes possible a comparative assessment of the oxidative stabilities of the oils studied. Such assessments can be performed only for oils not reprocessed which show PV less than or equal to 30 mmol O-2(2-)/kg of oil. The use of pressure differential isothermal calorimetry enables a more rapid stability assessment than the use of PV measurements alone.