During the period from 1985 to 1988 we determined 228 strains of streptococci isolated from samples of various sorts of biomaterials, mainly animals. From this set of streptococci we classified 207 strains into serological groups according to the Lancefield classification and about 30% strains into species by means of serological and biochemical methods. Most of the strains were allocated to group C (37.28%) and group Q (17.39%). 89 streptococci strains originated from pigs, 40 strains from horses, 13 from cattle, 12 from dogs, 9 from poultry and 8 from coypu. The other streptococci strains originated from other animal species or from different material. Most serological groups of streptococci were determined in pigs, less in cattle (7), in poultry (6), in dogs (6), in horses (5) and in coypu (3). Streptococci of the serological group Q were determined in as many as 9 animal species, group C in 8 species and group G in 6 species.