The purpose of the study was to investigate the effectiveness of a three-phased self-directed model in enhancing the social problem-solving skills and the levels of self-determination of students with ASD. A total of 44 junior high school students with ASD were assigned to either an experimental group (n = 24) receiving the three-phased self-directed instruction or a no specific treatment control group (n = 20). Data analysis included bivariate tests and hierarchical linear modeling to analyze teacher- and student-rated scores of social problem-solving (2 domains) and self-determination (4 domains). The findings of this study suggested that after controlling for cognitive functioning and peer/teacher support, (a) students who received the instruction significantly improved their social problem-solving skills when rated by teachers, as compared to those who had not received the intervention; and (b) the participants receiving the self-directed social problem-solving model intervention also made improvements in several domains of self-determination albeit results were not significant. The significant group-by-time effects on social problem-solving implied the effectiveness of the social problem-solving model, meaning that students with ASD became more self-directed problem solvers with the completion of the three phases of intervention.