Special education teachers in California acquire advanced degrees, credentials, and authorizations to serve students with disabilities who are English language learners (SWD-ELLs), yet continue to be challenged to meet the complex instructional needs of these students. Performance on statewide tests of achievement show continued disparities between the academic achievement of SWD, ELLs, and their non-disabled English-only speaking peers. Bandura's theory of self-efficacy was the theoretical foundation for this research study given that teachers' perceptions of their abilities across the span of their careers can directly affect the achievement of their students. To compare and examine the self-reported sense of self-efficacy of special education teachers in California who serve SWD-ELLs, a concurrent mixed methods design was used. Quantitative, Analysis of variance (ANOVA) and F-tests were utilized to determine statistical significance between the self-reported ratings of novice and experienced special education teachers (N = 67) on the Teachers' Sense of Self Efficacy Scale (TSES) questionnaire. Statistically significant differences between the 2 groups of teachers were not found. Coding and thematic analysis of teachers' responses to qualitative open-ended questions resulted in teachers reports of having received some training related to teaching SWD-ELLs. Both teacher groups also expressed a desire for mentorship, in-class coaching, collaborative training with parents, and cooperative training with general education teachers, to increase their ability to meet the complex instructional needs of SWD-ELLs. Results of this study provides educational leaders with insight regarding the needs of special education teachers in California to effectively increase educational outcomes for SWD-ELLs. [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.]