Under the carbon monoxide (CO) poisoning surveillance system established by the 2004 Public Health Act and the National Health and Environment Plan, and implemented by the French Institute for Public Health Surveillance (InVS), all suspected cases of CO poisoning must be reported (with the exception of poisonings occurring during a fire). The purpose of this system is to prevent the risk of recurrence, assess the incidence of such poisonings, and describe the circumstances and risk factors in order to develop appropriate prevention policies.