This paper describes the results of 2017-2020 fieldwork at the Upper Palaeolithic site of Kostenki 17 (Spitsynskaya). This work established the presence of five new horizons of finds, in addition to the two cultural layers known since the 1950s. Given the thickness of the Upper Humic Bed, it is clear that the horizons of finds are separated by sterile layers, and correspond to the existence of different sites on this part of the promontory. Despite the small number of finds, the contents of each horizon differ in both the composition of faunal remains and lithic artefacts, as well as raw materials, state of preservation and degree of weathering. The investigated area of the lower (second) cultural layer demonstrates a complex nature of the post-deposition processes that influenced its preservation. A sharp slope of the Lower Humic Bed and a significant difference in the depth of the finds indicate a partial displacement along the slope of some sections of the cultural layer, which was not recorded in previous excavations. The present publication includes a stratigraphic characterization of deposits, a description of the occurrence of the cultural layers and horizons of finds, preliminary results of a technical and typological study of new collections of stone tools and ornaments from cultural layer II, and the results of radiocarbon dating.