An outbreak of Shiga toxin-producing Escherichia coli infection occurred in France in June–July 2011. Eighteen cases were identified. These cases were children aged 6 months to 10 years who developed hemolytic uremic syndrome following prodromal diarrhea that occurred between June 6 and July 15, 2011. Fourteen cases resided in the Nord-Pas-de-Calais region. Sixteen cases were caused by E. coli serogroup O157, 1 case by serogroups O157-O177, and 1 case by serogroups O157-O26. All O157 serogroup strains isolated from the cases’ stool samples were non-motile and fermented sorbitol, a characteristic very rare for O157 strains isolated in France. Epidemiological, microbiological, and traceability investigations showed that this outbreak was linked to the consumption of ground beef (ground beef patties and burgers). This outbreak, the second in France linked to the consumption of ground beef patties, underscores the importance of thoroughly cooking this product for young children. (R.A.)