This study investigated the fatty acid composition of Eurasian perch, (Perca fluviatilis L.) from pond polyculture with (White Rawska), and populations from Lakes Mosg and Wadg. The eicosapentaenoic fatty acid EPA in muscles of the examined groups did not differ (P>0.05). A lower content of eicosapentaenoic fatty acid was noted in the liver of perch from Lake Mosg than the other fish examined (P0.05). Docosapentaenoic fatty acid DHA content in the liver of perch from Lake Wadg (23.03%) and the pond-cultured perch were higher than in the perch from Lake Mosg (P0.05). The pond-cultured perch (P0.05) had significantly lower content of docosapentaenoic fatty acid in muscles. The muscles of perch from Lake Wadg (38.61%) contained more n-3 polyunsaturated fatty acid PUFA than the other studied fish (P0.05), whereas the liver of fish from this lake (32.32%) and pond (33.73%) had higher values of n-3 polyunsaturated fatty acid PUFA than perch from Lake Mosg (24.62%) (P0.05). Fish had a higher content of n-3 polyunsaturated fatty acid than n-6 and low levels of fat and may be an important dietetic fish food from a consumer health point of view.