OBJECTIVE: To document the absenteeism costs associated with obesity and morbid obesity by occupation. METHODS: Data from the Medical Expenditure Panel Survey for 2000-2004 are examined. The outcomes are probability of missing any work in the previous year and number of days of work missed in the previous year. Predictors include clinical weight classification, age, education, and race. Models are estimated separately by gender and occupation category. RESULTS: The probability of missing work in the past year, number of days missed, and costs of absenteeism rise with clinical weight classification for both women and men, and vary across occupation. Absenteeism costs associated with obesity total $4.3 billion annually in the United States. CONCLUSION: Substantial absenteeism costs are associated with obesity and morbid obesity. Employers should explore workplace interventions and health insurance expansions to reduce these costs.