In 2004 and 2009-2010 we studied the composition of the food boluses in the Arctic grayling Thymallus arcticus (Pallas, 1776) from the two stretches of the middle reach of the Yenisei River. The food boluses contained larvae, pupae and imagoes of insects, centipedes, crustaceans, oligochaetes, gastropods, teleost fish eggs, higher plant seeds, stones and woody debris. In terms of mass, the ration consisted mostly of amphipods (Eulimnogammarus viridis, Eulimnogammarus cyaneus; Pallasea viridis), caddis worms (Apatania crymophila) and chironomids. During a year the ratio of the food key components changed. Amphipods were the main food of the Arctic grayling in summer and autumn, while in winter and spring the fish generally fed on caddisfly larvae and pupae. It was only in June that the percentage of chironomids was considerable (18%).