This study aimed to investigate the association between self-reported sleep duration and general and abdominal obesity in Korean adults. A total of 8,717 adults aged 20-65 years from the Korean National Health and Nutrition Examination Survey (KNHANES) 2001 and 2005 were included. General obesity was defined as BMI >or=25 kg/m(2) and abdominal obesity as waist circumference >or=90 cm in men and >or=85 cm in women. To control for sociodemographic and lifestyle factors and comorbidities, multivariable logistic regression was used to calculate the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of general and abdominal obesity across the following sleep duration categories: <or=5, 6, 7, 8, and >or=9 h/day. Mean sleep duration (+/-s.d.) was 6.9 +/- 1.3 h. Those sleeping <or=5 h/day had the highest BMI and waist circumference compared with those sleeping 7, 8, or >or=9 h/day (P < 0.05 for all comparisons). After controlling for sociodemographic and lifestyle factors, the adjusted ORs (95% CIs) associated with sleeping <or=5 h/day (vs. 7 h/day) were 1.25 (1.06-1.48) for general obesity and 1.24 (1.03-1.48) for abdominal obesity. Further adjustment for hypertension and diabetes mellitus did not significantly affect the associations. These data suggest that short sleep duration is significantly associated with a modest increase in general and abdominal obesity in Korean adults.