ABSTRACT: OBJECTIVES:To assess the association between sleep duration and health-related quality of life (HRQOL) among adults with or without chronic conditions. METHODS:Using the 2014 Behavioral Risk Factor Surveillance System, we analyzed self-reported data from adult respondents aged ?18 years with (n=277,757, unhealthy group) and without (n=172,052. healthy group) reported history of any of nine chronic conditions (coronary heart disease, stroke, cancer, chronic obstructive pulmonary disease, diabetes, asthma, arthritis, depression, chronic kidney disease). Multivariable logistic regressions were separately constructed to assess the associations between sleep duration and four self-reported HRQOL measures after adjustment for sociodemographics, leisure-time physical activity, body mass index, and smoking status among unhealthy and healthy adults. RESULTS:The prevalence of poor/fair health, frequent physical distress, frequent mental distress, frequent activity limitation, and short sleep duration was 27.9%, 19.3%, 17.0%, 13.6%, and 38.3% in the unhealthy group and 6.9%, 4.0%, 5.3%, 2.1%, and 31.0% in the healthy group, respectively. U-shaped relationships of sleep duration to all four HRQOL indicators were observed among the unhealthy group and to poor/fair health, frequent mental distress, and frequent activity limitation among the healthy group. The relationships further varied by sex, age, race/ethnicity, and BMI category among the healthy group. CONCLUSIONS:Relationships between extreme sleep duration and HRQOLs were observed among both healthy and unhealthy groups. These results can help inform public awareness campaigns and physician-counseling regarding the importance of sleep for mental health and well-being.