This study aimed to add to the limited research on principal self-efficacy in special education leadership and examine the link between principal preparation programs and special education leadership self-efficacy. The study further sought to examine how self-efficacy beliefs may influence principals' engagement in special education leadership behaviors. The theory of planned behavior provided a theoretical framework for this study and conceptualizes how the strength of self-efficacy beliefs, or perceived behavioral control, facilitates or impedes behavior outcomes (Ajzen, 1991). The researcher used a convergent mixed methods research design. The SELAS survey, open-ended questions, and interviews were used to collect data. The population of the study consisted of 143 New Jersey public school principals. Qualitative data were coded and analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), and multiple regression analysis were used to analyze the data. The analysis identified statistically significant differences in special education leadership self-efficacy among principals who held a Teacher of Students with Disabilities or Teacher of the Handicapped certificate and those who did not. In addition, statistically significant differences existed among four of the seven special education leadership tasks based on the number of special education courses completed by principals. Finally, there was a correlation between the number of years a principal taught special education and self-efficacy for special education leadership. No correlation was found between special education leadership self-efficacy scores and the number of years in the role as a school principal nor the presence or absence of building level special education support staff. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]