This study addressed the problem that teachers have had minimal or no training in how to implement evidence-based practices when educating students with Autism Spectrum Disorder (ASD); consequently, teachers struggle with which intervention to implement and when to implement the intervention. The purpose of this qualitative case study was to understand teachers' perspectives and experiences on instructing students with ASD and their use of evidence-based strategies with these students. The research questions sought to identify the perceptions and experiences of teachers when teaching students with ASD, along with their training. Twenty high school general education teachers completed a survey indicating the level of training they had received in evidence-based practices at the pre-service teacher education programs and while currently teaching. The findings indicated that the teachers had received minimal to no training in these practices. Following the survey, seven teachers participated in a semi-structured interview. The findings indicated that teachers rely heavily on their own experiences when educating students with special needs, especially students with ASD. The findings also revealed that the teachers would like to have training in effective researched-based strategies. It is recommended that a plan be implemented to train teachers and pre-service teachers, such as professional development activities, providing access to proven strategies, and creating coursework to address evidence-based practices. It is recommended that school districts prioritize training teachers who instruct students with special needs, including ASD. It is also recommended that pre-service teacher education programs include coursework in autism and evidence-based practices to prepare teachers when instructing students with ASD. This type of training is essential for the effective education of students with ASD. [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.]