Context: Numerous studies have demonstrated that obese individuals experience significant impairments in quality of life as a result of their obesity, with greater impairments associated with greater degrees of obesity. Aims: To assess the quality of life (QOL) and its clinical and sociodemographic determinants among adolescents and adult obese patients (>12 years old) attending obesity and/or nutritional clinics at Aseer Central Hospital, Abha, KSA. Setting and Study Design: This cross-sectional study was conducted in Aseer central hospital. Subjects and Methods: A cross-sectional study was carried out among a representative sample of all obese patients attending nutrition and obesity clinic at Aseer central hospital for a period of 2 months. A self-administered questionnaire was used to collect data. Statistical Analyses: Statistical Package for the Social Sciences (SPSS) ver. 20 was used to do the statistical analyses. Results: Overall, 198 obese patients completed the questionnaire and measurements gave a response rate of 84.3%. Their age ranged between 19 and 56 years with a mean age of 31.6 years and standard deviation of 6 years. In total, 56.1% were females. Conclusions: The study showed that the severe obese individuals (grade 3) suffer from poorer health-related QOL (HRQOL) compared to those of grades 1 and 2, as the increase in body mass index (BMI) lowers the HRQOL domains.