In the present study, were determined the basic nutrients (dry matter, crude ash, crude protein, ether extract, and energy) and mineral elements content in chosen species of raw and smoked freshwater and sea fish. The content of dry matter, and basic nutrients and Na+, K+, Ca+2, Mg+2, P+2, Zn+2, and Cu+2 in the fish samples was determined. The dietary intake of several macro- and microconstituents per one serving (150 g fresh or smoked fish) was calculated. The fresh fish contained on average 220.2 to 283.7 g·kg−1 of dry matter, 12.4 to 10.7 g·kg−1 of crude ash, 176.2 to 173.5 g·kg−1 of crude protein, 32.6 to 78.6 g·kg−1 of ether extract, and 104.6 to 119.1 kcal (freshwater and sea fish, respectively). Thermal treatment reduces the water and fat content in fish meat. Reduction of the K, Ca, Mg, P, Zn, and Cu levels was observed most frequently. The one serving of fish covers approximately 23% and 12% of the recommended dietary amount of K, 7.5–5.0% of Ca, ~12% of Mg, 6.8 to 12.5% of Zn, and about covered 6.7% of Cu. The smoking process increased the concentration of some basic nutrients and reduced the fat and mineral content. Whitefish, trout, halibut, mackerel, and herring had the highest levels of the analyzed minerals.