In response to the growing number of foodborne illness outbreaks associated with Bacillus cereus, a phenotypic and genotypic characterization of isolates from suspected food sources was conducted and analyzed in relation to the clinical symptoms of reported cases. Between 2006 and 2010, 55 reported outbreaks were investigated. The combination of the various markers examined (hemolysin, starch, production of Nhe and Hbl toxins, detection of the ces, cspA, cyt K1, and cyt K2 genes) allowed the 279 analyzed isolates to be classified into 19 distinct profiles. Some of these profiles could be associated with one of the seven phylogenetic groups previously described in B. cereus sensu lato. Taken together, these results confirmed i) the diarrheal or emetic potential of most strains, ii) the involvement of groups III, IV, V, or II in foodborne illness outbreaks, whereas strains from group VI do not appear to be pathogenic, iii) the emergence of particularly virulent strains from group VII. This study highlights the importance of characterizing strains in conjunction with available epidemiological data to improve surveillance of Bacillus cereus foodborne illness. (R.A.)