Data on the fauna and the spatial distribution of aquatic oligochaeta for the whole area of the Gusinoe Lake, which is the second lake on the area in the Lake Baikal basin at the territory of Russia, were obtained for the first time. There are 23 species taking into account the new data (17 species) which inhabit the lake. The 7 species have cosmopolite type of distribution, 10 species – Holarctic, 3 – Palearctic, 1 species – East Palearctic and 2 species with unascertained type of distribution. The most common species in the lake are Potamothrix bedoti (Piguet, 1913), which inhabits 35 stations (61 % of occurrence), Tubifex tubifex (Mueller, 1773) – 33 stations (58 %), and Limnodrilus hoffmeisteri Claparede, 1862 – 29 stations (51 %). The spatial distribution of oligochaeta in the lake is presented along with the information on coordinates, depths, sediments and aquatic vegetation of 57 studied stations.