Because essential fatty acids have an important role in human health, there is a growing interest in fatty acids profile and nutritional quality of fish, originating from both marine and freshwater resources. This research was performed to determine the seasonal changes in nutritional quality, fatty acids composition and energy contents of Prussian carp inhabiting in Lake Çıldır, Turkey. Fatty acids profile demonstrated high monounsaturated fatty acids content that was changed from 44.82 in spring to 41.28% in autumn. Saturated fatty acids (SFA) content was changed from 30.35 in summer to 29.40% in autumn. Polyunsaturated fatty acids (PUFA) content was the highest in summer (25.02%) and the lowest in spring (21.52%). Major fatty acids were palmitic, oleic, linoleic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Lipid quality indexes were within the range of recommended levels for human health. According to the results biochemical composition of Prussian carp is similar in all seasons, in terms of fatty acids, the autumn season can be the most suitable season for consumption. Although being an underutilized fish species for its taste, smell, high string structure and unpleasant textural features, Prussian carp has a good quality by means of protein and essential fatty acids.