Within the Russian-German collaborative research project The Changing Arctic Transpolar System (CATS; see www.transdrift.info), benthic species distributions have been modelled across large geographic scales in Eurasian Arctic seas. As surficial seafloor sediment grain size is one important explanatory variable used in these modelling studies, we compiled open-access information from 23 data sets on this environmental parameter, pooling validated grain-size data from a total of 2,134 sampling sites distributed across the Barents, Kara, Laptev and East Siberian Seas, as well as some abyssal regions of the central Arctic Ocean. As grain-size distributions are differently scaled in western European and Russian sources, all data were uniformly transformed to the Udden-Wentworth scale using the "approximation" function in R prior to further processing and archiving. For this, a linear interpolation was utilized to split the 50-100 µm grain-size fraction used in Russian data sets into the silt (≤ 63 µm) and sand (> 63 µm) fraction of the Udden-Wentworth scale. Using the kriging R package "automap", interpolated maps were created showing the geographic distribution of the percentages (%) of fine (silt and clay: ≤ 63 µm) and coarse (> 63 µm to 2 mm) grain-size fractions in surface seafloor sediments. These maps were first created in the Sea Ice Polar Stereographic North CRS projection, followed by a transformation to the standard WGS84 CRS projection.