Promoting active student involvement in transition planning has become best practice in promoting self-determination. This study examined the contribution of self-determination to transition planning knowledge and skills for 180 students with disabilities. Utilizing multiple regression analyses, the study found that global self-determination was a significant predictor of overall transition planning knowledge and skills, as well as of transition planning factors related to knowledge and skills about the individualized education program team process, goals, and decision making. Furthermore, when self-determination was broken into its component elements and included in the analyses, those elements, particularly self-regulation and self-awareness/self-knowledge, became the sole predictors of transition planning knowledge and skills.