Gifted students with high functioning autism (gifted-HFA) are being excluded from gifted programs in one public school setting in the Southeastern United States designed for gifted and high-achieving students. Although the literature indicates teacher self-efficacy in working with this group can contribute to this problem, it was unclear whether teachers in this specific setting experienced self-efficacy challenges. The study's purpose was to understand teachers' sense of self-efficacy when teaching gifted-HFA students. The conceptual framework that drove this study was Bandura's self-efficacy theory. Using a basic qualitative method, interviews were conducted with eight gifted endorsed teachers who had experience teaching gifted-HFA students. Open coding and thematic analysis were used to analyze the data. Results indicated that teachers of gifted students experienced a lower sense of self-efficacy regarding teaching gifted-HFA students. Participants reported this resulted in part from a lack of preservice training and a need for ongoing professional development to improve their ability to meet gifted-HFA students' needs. This study's findings may be used by school administrators and gifted program directors as the basis to identify and implement training opportunities for teachers of gifted students to increase their teaching capacity and self-efficacy. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]