Regular physical activity, sports participation, and active recreation are essential behaviors for the prevention of disease, promotion of health, and maintenance of functional independence. This health behavior is essential for persons with and without disabilities. Population-based surveys have consistently demonstrated that persons with disabilities are less likely to be physically active, compared to persons without such limitations. However, these observations are based on relatively few surveys and are dependent on physical activity assessment methods that may not be sensitive and specific enough for persons with disabilities. Studies clearly demonstrate that many persons, representing a variety of selected disabilities, can adapt to increased levels of physical activity, as evidenced by alterations in various components of physical fitness. More importantly, other studies consistently provide evidence that participation in regular physical activity among persons with selected impairments and disabilities results in improved functional status and quality of life. Further efforts are critically needed in the area of the development of physical activity assessment methodology for persons with disabilities. Methods need to be developed that will provide survey researchers and those in public health the capacity to measure and monitor activity patterns of persons with disabilities. This information is important not only for public health officials but also health policy analysts, service providers, and disability advocacy groups. Further understanding of the role of physical activity in the maintenance of function and independence among persons with disabilities is needed. The understanding of environmental and social barriers to physical activity among persons with disabilities needs further exploration. Finally, physical activity determinants research among persons with disabilities, including the role of assistive technology as well as maximizing the intrinsic capacity of functional anatomy and physiology, needs to be addressed.