BACKGROUND: Obesity is not only a health problem but also a socioeconomic problem. The aim of this study was to focus on the economic aspects of obesity related problems by examining the associations between obesity and occupation among Korean adults using nationwide surveys. METHODS: This study includes 457 morbidly obese adults (body mass index > or = 30 kg/m2) including 188 men and 252 women and 457 normal weight control adults matched by sex, residing area (urban, rural), and age (per 5 years) using the 4th Korea National Health and Nutrition Examination Survey. The socioeconomic state, employment rate, the industrial and occupational classification of jobs they served were compared. The Korean Standard Industrial Classification 8th revision and the Korean Standard Classification of Occupation 6th revision were used for job comparisions, respectively. RESULTS: For men, the standardized household income level did not difffer between the morbidly obese group and the normal weight group (P = 0.463). However, morbidly obese women showed a significantly lower household income level (P = 0.002). Neither employment rates nor occupational classification of jobs differ according to body weight for both men (P = 0.161) and women (P = 0.285). However, the morbidly obese men were less likely to be engaged in manufacturing industry (10.5% vs. 15.3%, P = 0.034), while the morbidly obese women were less likely to serve in public or personal service industry (10.5% vs. 19.9%, P = 0.036). CONCLUSION: The normal weight group and the morbidly obese group differed in terms of socioeconomic status and also in terms of industrial classification of jobs they served. These associations differed by sex.