Foraminifera of the Lower and Middle Portlandian and Ostracods of the Purbeckian facies of the Upper Portlandian of Polish Lowlands were studied; 63 foraminiferal species (including 12 new) and 21 ostracod species (including one new, Cypridea praealta sp.n.) are described. Analysis of stratigraphic ranges of the microfauna made it possible to distinguish 5 foraminiferal zones (I-V) of the Lower and Middle Portlandian and 5 ostracod zones (F-B) of the Purbeckian facies of the Upper Portlandian. The foraminiferal microfauna of the Portlandian of Poland appears most similar to those from the Lower and Middle Volgian of the Russian Platform.
Thirty five Lower Kimmeridgian ostracod species, including 13 new ones, assigned to 9 families, are described. They come from five borings at Strzałków locality (NW border of the Holy Cross Mts.). A subdivision of the Lower Kimmeridgian of this region into 3 ostracod horizons is proposed. The Lower Kimmeridgian ostracod assemblage of this region resembles those of the contemporaneous deposits in Central and Northern France, Southern England, Northwest Germany, Denmark and of the Swiss Jura.