An increased rate of Clostridium difficile-associated diarrhea (CDAD) was noted in two intensive care units of a university-affiliated tertiary care facility. One unit instituted enhanced environmental cleaning with a hypochlorite solution in all rooms, whereas the other unit used hypochlorite solution only in rooms of patients with CDAD. The CDAD rates decreased in both units. Infection Control and Hospital Epidemiology 2007;28:205-7 [Epub 2007, Jan 26].