OBJECTIVE: To examine the associations of abdominal fat and obesity with functional limitations and disability in late adulthood. DESIGN: Longitudinal, cohort study. PARTICIPANTS: African American and white men and women aged 45-64 y at baseline with measured waist circumference, waist-to-hip ratio (WHR), and body mass index (BMI) who participated in the Atherosclerosis Risk in Communities (ARIC) Study (n = 9416). OUTCOME MEASURES: Self-reported functional limitations, activities of daily living (ADLs), and instrumental activities of daily living (IADLs) at ages 52-75 y. RESULTS: Waist circumference, WHR, and BMI were positively associated with functional limitations and ADL and IADL impairment approximately 9 y later among African American and white men and women. For example, in African American women the odds ratios (95% CI) associated with a one standard deviation (s.d.) increment in waist circumference (13.3 cm) for severe functional limitations and ADL and IADL impairment were 2.36 (2.00-2.79), 1.41 (1.25-1.58), and 1.49 (1.34-1.66), respectively. In white women, the odds ratios (95% CI) were 2.66 (2.39-2.96), 1.60 (1.47-1.74), and 1.42 (1.31-1.53), respectively. Similar associations were found in men. A 1 s.d. increment in WHR (0.08 U) and BMI (5.06 kg/m2) produced similar results. The associations of waist circumference and WHR with functional limitations and ADL and IADL impairment were attenuated but, in general, remained statistically significant when BMI was added to the models. CONCLUSIONS: Maintaining a healthy body weight and avoiding increases in abdominal fat should be investigated for their potential to reduce the risk of functional limitations and disability in an aging population.