Introduction: Although health authorities and civil protection agencies launch carbon monoxide (CO) poisoning prevention campaigns every year, this gas remains the toxin responsible for the highest number of acute poisonings in France (2,000 to 3,000 cases annually). To better tailor messages and communication methods to the public’s needs, a survey on awareness of CO risk was conducted among the adult population of Lot-et-Garonne. Method: A random sample of 500 people was interviewed by telephone in September 2006. The questionnaire focused on environmental and health-related awareness of CO risk as well as preferred methods of receiving information about this risk. Sociodemographic information and housing characteristics were also collected. Results: Nearly 87% of respondents had heard of CO. This proportion is significantly linked to educational attainment, ranging from 75% among those without a degree to 98% among those with a college degree. About 88% correctly identify it as a gas, but only 53% know that it cannot be detected by the senses, and nearly one-third believe that CO can be recognized by its smell. Nearly 94% believe that CO can have health effects, but awareness of the signs of poisoning ranges from 92% for headaches to 62% for visual disturbances. 79% identify natural gas as a fuel posing a CO risk, while awareness of the risk associated with wood varies significantly by age: 20% of those under 30 versus 70% of those over 60 are aware of this risk. Regarding preferred sources of information, television (62%) is the most frequently cited medium, regardless of age, gender, or educational level. Brochures, posters, and radio receive scores below 20%, with significant disparities across sociodemographic categories. Brochures are three times less popular among people with the lowest level of education than among those with a college education. Discussion-conclusion: Although the vast majority of adults in Lot-et-Garonne have already heard of CO and are aware of the health risk, a much smaller proportion actually knows its technical characteristics and the signs of poisoning. Knowledge varies across sociodemographic categories. Furthermore, without prejudging the effectiveness of available communication methods, the results obtained highlight the need for careful consideration regarding information materials. (R.A.)