During an 18-month period all stools submitted to a microbiology laboratory in Belgium for culture were screened for Verocytotoxin-producing Escherichia coli (VTEC) serotype O157. In the stool samples from 3940 patients, eight (0.2%) VTEC O157 strains were isolated, seven of which were O157:H7. Additional screening for other serotypes of VTEC in 332 selected stool samples yielded four more strains (serotypes O2:K1:H6, O111:H-, O117:K1:H7 and O"C70/86":H-). The 0.3% isolation rate for all VTEC was comparable to that for Shigella spp. Eight children under 30 months and two adults suffered from uncomplicated gastroenteritis. A 5-month-old child and a 41-year-old woman presented with hemolytic uremic syndrome a few days after onset of a diarrheal episode.