During a palynological analysis of four samples from the Bełchatów KRAM-P 218 collection of plant macroremains 95 fossil species of sporomorphs were identified. Among the non-pollen palynomorphs was the fossil species Desmidiaceaesporites cosmarioformis, previously not reported from fossil floras of Poland, most probably related to the zygospores of desmids. The pollen analysis indicates the presence of a freshwater body (probably an oxbow lake) and shows the dominant role of wetland, predominantly riparian vegetation, at the time of sedimentation. The riparian forests probably consisted of Carya, Pterocarya, Celtis, and Ulmus, accompanied by Alnus, Acer, Fraxinus, Juglans, Liquidambar, Vitis, Zelkova, and Salix. In mixed forests there probably were Fagus, Quercus, Carpinus, Eucommia, Corylus, Tilioideae, and conifers, as well as some thermophilous taxa (e.g. Castanea, Symplocos, Reevesia, Mastixiaceae, and plants producing pollen of the fossil species Tricolporopollenites pseudocingulum). Taxodium, Nyssa, and presumably Glyptostrobus and Alnus were components of swamp communities that might have overgrown the adjacent area with higher groundwater. Members of the families Ericaceae, Cyrillaceae, and Clethraceae, as well as Myrica and probably also Ilex, may have been components of swamp forests and bush swamps. Our analysis indicates that the climate was warm temperate and moderately wet. The palynoflora is most similar in composition to the spore-pollen spectra of the X climatic phase – the Nyssapollenites spore-pollen zone. Deposits bearing assemblages of the Nyssapollenites spore-pollen zone were deposited during the Sarmatian and early Pannonian. Our results are consistent with those from plant macroremains from the same collection.