EN
Blood plasma from 140 specimens of cattle from different regions of Poland have been directly examined after rotation in hematocrit microtubes acc. to the method by Kingston and Morton (11). Trypanosoma theileri Laveran, 1902 were found in blood of 20% of cattle from the forest-villages in Białowieża Forest (Białystok district) and in 6.8% of cattle in Zamość district. There were not found the evidence of protozoans of this species in blood samples of cattle from Warszawa, Włocławek and Przemyśl districts.