Polyunsaturated fatty acids (PUFAs, LA and ALA) are not synthesized in mammals in the absence of their essential fatty acid precursors. However, hibernating animals and animals sleeping through the winter need sufficiently high amounts of these acids. The Eurasian badger does not hibernate, but sleeps over winter. In the autumn the body weight of adult badgers increases even twofold, since they put on fat before the winter. Fat is deposited primarily in the subcutaneous layer of adipose tissue, and much less commonly in the muscles, liver and around the intestines. The percentage composition of fatty acids (Saturated fatty acids-SFAs, monounsaturated fatty acids-MUFAs, PUFAs) is different in particular types of tissue. The lipids isolated from depot adipose tissues (suet, subcutaneous, perirenal, periintestinal fat) are dominated by monounsaturated fatty acids (on average 41.25%), followed by saturated fatty acids (33.53%). Polyunsaturated FAs have the lowest proportion in this groups of tissues, on average 17.75% of total FAs. On the other hand, liver lipids contain over 44% PUFAs. The fatty acid composition of lipids in badgers tissue includes considerable quantities of essential unsaturated n-6 and n-3 fatty acids of great pharmacological significance.