While our knowledge about the cognitive and social components of disability continues to grow, little is known about how the self specifically develops in adolescents with physical disabilities and whether a specific source is an indicator of self-determination with this population. Adolescents who have a physical disability may have difficulty progressing through the stages to become self-determined because they are often viewed as needing protection, which often takes the form of others making decisions for them. Decision makers may assert that the adolescent with a physical disability is not capable of making good decisions and the consequences of such decisions are likely to be harmful. Therefore, the present article explores the difference between adolescents with and without physical disabilities with respect to self-concept, self-esteem, locus of control, self-efficacy, and self-determination and investigates the self-reported relationship levels of these indicators to determine if there is one single best predictor of self-determination for adolescents with and without physical disabilities.