During 5 y (1997-2002) in the region of Lower Silesia, Poland, 55 shiga-like toxin-producing strains were isolated from children with diarrhoea, none of whom developed haemolytic uremic syndrome. Shiga-like toxin production was detected on Vero cells and confirmed by the detection of slt1 and slt2 gene sequences. Most of isolates examined possessed slt2 gene alone (41.8%), or in combination with slt1 gene (38.2%). None of the shiga-like toxin-producing strains was of serotype O157:H7. It appears that non-O157 shiga-like toxin-producing E. coil strains are prevalent as the causal agent of severe diarrhoea in the region.