The distribution of the Kildin cod Gadus morhua kildinensis in Lake Mogilnoye (Kildin Island, Barents Sea) is assessed based on the results of echo sounding and hydrological surveys, underwater photography and field observations. Underyearlings live in the lower part of the freshened upper layer, younger age groups locate in vicinity of the natural dam in the southeastern part of the lake, adults are distributed along the water area of the lake within the depth range of 4.0–6.4 m (mainly 5.0–5.4 m), characterized by favorable temperature values, water salinity, and oxygen saturation.