Bacillus cereus Hemolysin BL is a tripartite toxin responsible for a diarrheal type of food poisoning.We found distinct complexes of up to 600 kDa on native gels, whose structure and size were primarily defined by Hbl B. Hbl L1 and L2 were also identified in these complexes using Western blotting and an LC-MS approach. LC-MS also revealed that many other proteins secreted by B. cereus exist in complexes.