Objective.—A U-shaped association has consistently been demonstrated between sleep duration and several comorbidities, including obesity, type 2 diabetes, accidents, and cardiovascular diseases. However, while the risks associated with insufficient sleep are well established and understandable, those associated with “sleeping too much” are not well understood. The aim of our study is to explore the sociodemographic characteristics and comorbidities associated with self-reported sleep duration exceeding 10 hours in a representative sample of adults in France. Methods.—As part of the 2010 Health Barometer, a representative sample of 24,671 adults aged 15–85 was surveyed about their sleep habits and associated comorbidities. An average total sleep time (TST) on weekdays was calculated using a sleep diary-style questionnaire. Those reporting a TST > 10 hours per day were considered “long sleepers.” "Short sleepers" were defined as those with a TST < 5 hours. Results: The mean TST was 7 hours and 13 minutes (± 1 minute). Six hundred twelve subjects were long sleepers (2.7%) and 1,969 were short sleepers (7.5%). Compared to the total group, "long sleepers" were more likely to be women, young (15–25 years old) or older (over 65 years old), without a degree, and employed as office workers or manual laborers. They had significantly more psychiatric disorders and a higher body mass index (BMI). However, no significant association was found with other diseases. Conversely, "short sleepers" are significantly more affected by both psychiatric disorders and most other chronic diseases. Conclusion: In the general population, "sleeping too much" may be associated with psychiatric disorders and a higher BMI but not with other chronic diseases. Source: poster cited in the journal "Médecine du sommeil," Issue 1, Volume 11.