Self-determination has been a primary focus of efforts to enhance quality of life for individuals with disabilities. Learning self-determination enables individuals to assume greater responsibility and control in their lives. The primary causal agency perspective on self-determination highlights the importance of learning self-determination for all individuals regardless of the severity of their disabilities. Examination of the perspectives of adults who have disabilities on their experiences of learning self-determination can provide valuable insights that can be applied to children and youths. In this study, we interviewed 10 participants from Taiwan, all of whom had severe to profound physical disabilities or multiple disabilities. Data were analyzed thematically, and the following themes regarding participants' self-determination experiences emerged: (1) beliefs about self-determination, (2) challenges from external interference, (3) challenges from societal and cultural influences, (4) peer support for self-determination, and (5) family support for decision-making. Findings are discussed along with implications for the teaching of self-determination practices to relevant stakeholders.