Bioerosion structures, including holes, pits, and grooves, on the surface of benthic foraminiferal  tests from the Upper Cretaceous and Paleogene of Western Siberia are studied. Their morphology is examined, their possible origin and the paleogeographic and stratigraphic distribution in sections representing marine basins of Western Siberia are discussed. The ichnospecies assemblage studied includes Oichnus simplex Bromley, 1981, O. paraboloides Bromley, 1981, O. gradatus Nielsen et Nielsen, 2001, and O. ovalis Bromley, 1993.