The paper presents an analysis of the genetic polymorphism of 83 E. coli isolates, derived from artiodactyla animals living in the area of ZOO Safari Swierkocin (Poland). The following species of animals were the source of the strains: Taurotragus oryx, Bos primigenius, Kobus ellipsiprymnus, Bubalus bubalis. Screening of pathogenic features revealed the occurrence of antigen O26 in 9 isolates from Bos primigenius. The rep-PCR fingerprinting method with ERIC-type primers was used in analysing the genetic polymorphism of the obtained E. coli strains. The fingerprint patterns indicated the essential polymorphism in the distribution of ERIC sequences in genomes of the examined isolates. The UPGMA statistical analysis of fingerprints, carried out with the use of Jaccard's coefficient, differentiated E. coli isolates into 7 groups. The degree of similarity between each pair of the compared groups, expressed in percentages, was found to be considerably different. Five of them (I, II, III, VI, VII) revealed a divergence of features (0% similarity), and the next tow (IV and V) 3% similarity. Segregation of the strains into groups varied in terms of number (from 1 to 47) as well as source of origin (the species of the animal). The isolates derived from all four sources were formed into groups IV and I. Group II comprised strains derived from three sources, while groups III, V and VII from two sources. One strain derived from a Taurotragus oryx was segregated into group VI. A complex structure of similarity was found within group IV. 47 isolates of group IV were segregated into 7 subgroups closely connected in terms of their source of origin and pathogenic feature of O26. The rep-PCR fingerprinting method with ERIC-type primers may be applied in epidemiological monitoring of large conglomerations of animals in order to control propagation of both comensal and pathogenci strains.