The first isolation and partial characterization of bovine foamy virus (BFV), also known as bovine syncytial virus, in Poland is described. This virus was isolated by co-cultivation of peripheral blood leukocytes from infected cattle with permissive Cf2Th cells. The new isolate, called BFV100 was identified using several techniques: electron microscopy, western blotting, PCR and sequencing of a part of the gag and pol/env genes. Based on syncytia induction, antigenic determinants, primer binding sites and sequence analysis, it can be concluded that isolate BFV100 is bovine foamy virus and is related to the known American and German BFV isolates by sequence homology and antigenic relatedness.