During a nine month survey in the Royal Zoological Society of Antwerp, E. coli O157 was isolated from six out of 300 faecal samples collected from 258 mammals, 33 birds and nine reptiles. Enterohaemorrhagic E.coli O157:H7 (EHEC) strains were isolated from a horse (Equus caballus) and two primates: a ring-tailed lemur (Lemur catta) and a goeldi's monkey (Callimico goeldii). Atypical E. coli O157 strains, which fermented sorbitol and were beta-glucuronidase positive, were isolated from two silvered leaf monkeys (Presbytis cristatus) and a ring-tailed lemur (Lemur catta). These strains were classified as enteropathogenic (EPEC), as they only possessed the eaeA gene as a virulence marker. With five isolations out of 48 samples, the primates can be considered a potential source of infection by E. coli O157.