Lipids obtained from the muscular and adipose tissues of the European beaver were isolated by the modified Folch method. Fatty acids were converted to methyl esters and separated by high-resolution gas chromatography (HR-GC). The content and composition of beaver fat depended on the sex of a given animal. The adipose subcutaneous tissue of the female contained the most fat (approximately 70.5%). The fat content of muscular tissue was very low in both male and female beavers. Adipose tissue lipids of the beaver contained fatty acids ranging in chain length from 12 to 22 carbon atoms. Polyunsaturated fatty acids have the highest proportion in of total FA content of adipose tissue in the beaver, which distinguishes these lipids from the lipids of adipose tissues in other mammals. The results of the present study also confirmed a unique FA composition in the tail fat of the beaver, including a very high content of alpha-linolenic acid (ALA, 18:3 n-3) (on average 20.0%) and the sum of n-3 fatty acids (on average 20.45%). In addition, a very low content of the sum of saturated fatty acids (on average 14.93%) was observed, and an extremely low content, as for animal fat, of palmitic acid 16:0 (on average 10.53%).