The foraminiferal and nannoplankton assemblages analysed in the Węglówka Marls, Subsilesian Unit, indicate the Campanian-Maastrichtian age. These sediments were deposited on the outer shelf and the upper-mid part of the slope. Palaeoecological analyses indicated a relationship between some morphotypes and their life strategies. Morphogroup analysis of the foraminiferids are indicative of palaeobathymetrical changes in the studied part of the basin, based on the relationship between keeled/non keeled taxa as well as on the quantitative distribution of the several benthic genera. The foraminiferids and the calcareous nannoplankton assemblages indicate the Tethyan/Boreal affinity.