In May 1992, a small, circumscribed community outbreak of infection due to verotoxin-producing Escherichia coli O157 phage type 49 occurred in a semi-rural area of south-east Scotland. On the basis of stool cultures, six cases were identified, one of whom was asymptomatic. One child developed the haemolytic uraemic syndrome. Although the source of infection of the index case was not established nor could the extent of person-to-person spread be fully determined, the clinical, microbiological and epidemiological evidence available indicated that a children's paddling pool served as the focal point in the transmission of infection causing the outbreak.