The Badenian/Sarmatian boundary in the Central Paratethyan basins is characterized by a change from open marine conditions during the late Badenian to the assumed brackish conditions during the early Sarmatian. Foraminiferal and palynological results of the Badenian/Sarmatian boundary interval in the Babczyn 2 borehole (SE Poland) showed that the studied interval accumulated under variable, unstable sedimentary conditions. The Badenian/Sarmatian boundary as correlated with a sudden extinction of stenohaline foraminifera is interpreted as due to the shallowing of the basin. The lack of foraminifera and palynomorphs just above the Badenian/Sarmatian boundary can reflect short-term anoxia. The composition of euryhaline assemblages characteristic for the lower Sarmatian part of the studied succession indicates marine to hypersaline conditions.