This short communication reports an assessment of the oxidation process of castor oil fatty methyl ester samples submitted to Rancimat (EN 14112) and PetroOXY (ASTM-D7545) oxidation methods. Fourier Transformed Infrared Spectroscopy (FTIR) was used to evaluate the FAME degradation products resulting front the accelerated oxidation, following the area of the carbonyl band (similar to 1740 cm(-1)) of the samples at different oxidation times. Our results indicate that the level of oxidation of castor oil FAME, using the Rancimat method, follows a similar pattern of the oxidized samples using the PetroOXY method. (C) 2011 Elsevier B.V. All rights reserved.