The fat contents and fatty acid compositions of three hazelnut cultivars; Tombul, Palaz and Kalinkara were investigated during storage at 21 degrees C with 60-65% relative humidity. The total fat contents of kernels in vacuum packages increased significantly with storage time. It is believed that the absolute value of fat content does not increase but that the kernel water content and total weight decrease. The palmitic and oleic acid contents of stored hazelnuts increased, while linoleic acid content decreased. No significant differences were found for stearic and linolenic acids during storage.