The objective of this study was to use performance-based measurements to identify, in a population of community-dwelling American Indians aged 55 and older, the prevalence and correlates of lower body functioning. Data were collected as part of a cross-sectional study of disability from members of a tribe in the southeast. Lower body functioning was measured using the Short Physical Performance Battery (SPPB), where higher scores reflect better functioning. Independent variables included age, sex, marital status, educational attainment, current cigarette smoking, physical activity, body mass index (BMI), hearing loss, vision loss, bone or joint trauma, chronic pain syndrome, osteoporosis, medical comorbidity, and depressive symptomatology. The total composite SPPB score (8.8 ± 3.4) declined significantly with increasing age and was negatively associated with unmarried status, physical inactivity, vision loss, bone or joint trauma, and medical comorbidity after adjustment for all other factors in the model. Likewise, all individual SPPB component scores declined significantly with increasing age and were negatively associated with physical inactivity and comorbidity. The balance test score was significantly and negatively associated with unmarried status and vision loss; gait speed was negatively related to unmarried status; and chair stand test score was negatively related to BMI, vision loss, bone or joint trauma, and chronic pain syndrome. In the clinical setting, the SPPB can be an important screening tool for adverse health-related events. Further studies are needed to investigate the determinants and sequelae of physical dysfunction in this population.