The article represents an analysis of the lithic collection excavated during numerous field researches of the Upper Paleolithic site Gerasimova I (located in Irkutsk) in 2007–2009. Cultural remains were found in 2 horizons. Lower, second horizon was recorded in soliflucted layer of the Upper Karga loams with radiocarbon ages dated 37–27 ka BP. The core reduction was aimed at shortened wide blanks with the exploitation of planar (more rare volume) parallel unidirectional and radial reduction system with a minimal preparation of preform. General types of tools are the following: side-scapers, end-scrapers, rare bifaces, knife-like and thorned tools. Upper, the first horizon of cultural remains was recorded at the bottom of the Lower-Middle Sartan loams with radiocarbon ages of 22–18 ka BP. The sparse lithic collection contains some indications of blade and microblade reduction. There were found edge-faced and prismatic cores, blade- and flake-based tools in collection. The lithic industry of the second horizon correlates with such assemblages as Mamony II (horizon 2), Shchapova I and Spartak I. First horizon’s materials are too scanty for correlations.