ABSTRACT: The paper presents results of detailed investigation of freshwater microalgae from the Upper Miocene deposits from JÃ³zefina (KrakÃ³w-Silesia Upland, central Poland). During the studies 28 microphytoplankton species of the genera Sigmopollis, Geiselodinium, Botryococcus, Ovoidites, Cycloovoidites, Stigmozygodites, Diagonalites, Tetraporina, Spintetrapidites, Closteritetrapidites, Planctonites,Cystidiopsis, Zygodites, andPseudoschizaea were identified. One new species,Closteritetrapidites pacltovae sp. nov. has been proposed.Most of the recorded algae preferred meso-to eutrophic, stagnant or slowly flowing shallow waters. The presence of resting cells – e.g. zygospores of Zygnemataceae (Mougeotia, Spirogyra, and Zygnema) and desmids (Closterium), suggests that the water body (bodies) might periodically dried out. The occurrence of Pseudoschizaea is characteristic forwarm climate, possibly with seasonal moisture fluctuations. Occurrence of determined species in various localities (listed in synonyms) suggests that these algae were widespread in the past.