The critical thinking skills of pre-kindergarten special education teachers needed for effective education of their students are currently not known. This study used a mixed methods multi-case study design to answer the question: What is the relationship between critical thinking and effective teaching for pre-kindergarten special education teachers? Vygotsky's theory of social constructivism guided the study design and data analysis of standardized measurements of critical thinking and effective teaching, observations, and interviews of ten pre-kindergarten special education teachers. Findings of the study included that a) the HCTA may not be a good measure of teacher critical thinking; b) teacher discussion of critical thinking related most closely to the CLASS dimension of concept development in the subcategory of instructional support; and c) teachers and pre-service teachers need opportunities to develop their knowledge base of behavioral and instructional strategies. [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/en-US/products/dissertations/individuals.shtml.]