OBJECTIVE: To examine the prevalence of overweight, obesity, and extreme obesity in a predominantly minority group of adults with disabilities. DESIGN: Cross-sectional study using secondary data analysis. SETTING: Major university medical center. PARTICIPANTS: Adults with physical and cognitive disabilities (N = 306). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Direct measures of height and weight to classify subjects into 3 obesity categories: overweight (body mass index [BMI] range, 25-29.9 kg/m2), obese (BMI range, 30-39.9 kg/m2), and extreme obesity (BMI, > or = 40 kg/m2). RESULTS: People with disabilities, regardless of sex, race and ethnicity, or age, had significantly higher rates of overweight, obesity, and extreme obesity compared with people without disabilities. Extreme obesity (BMI, > or = 40 kg/m2) was approximately 4 times higher among people with disabilities than in the general population (odds ratio = 4.08; 95% confidence interval, 3.50-4.66). There were also substantial differences in obesity prevalence among people with disabilities, using actual measurement data, compared with self-reported data from previously published data sets. CONCLUSIONS: The disparity in excess body weight between people with and without disabilities, particularly in the category of extreme obesity, along with substantial differences in obesity prevalence between actual and self-reported data, show a critical need to better understand why these differences exist.