This study examined differences in self-determination among students with autism spectrum disorders (ASD), students with intellectual disability (ID), and students with learning disabilities (LD). A total of 222 participants with an equal size group for each of the three disability categories were selected to participate in the comparison of total self-determination and domain scores. A multivariate analysis of covariance (MANCOVA) was performed on four dependent variables (DVs)/factors, including autonomy, self-regulation, psychological empowerment, and self-realization. The results indicated that students with ASD had significantly lower levels of autonomy compared with students in either other group; that students with ID had significantly lower levels of self-regulation than students with LD, but not significantly different from students with ASD; that students with ASD and students with ID had significantly lower levels of psychological empowerment than students with LD; and that students with ID had significantly lower levels of self-realization than students with LD, but not significantly different from students with ASD. Suggestions for future research and implications for educators were also discussed.