The hydroperoxides in oxidized mixtures of methyl oleate and linoleate were reduced to the corresponding hydroxyesters, which were separated from unoxidized esters by thin layer chromatography on silica gel. The hydroxyesters from oleate and linoleate were converted to trimethylsilyl ethers and separated by gas chromatography on OV 225. The results suggest that methyl linoleate oxidizes about ten times faster than methyl oleate, but oleate hydroperoxides are formed in appreciable amounts, even in mixtures containing 87% methyl linoleate.