The purpose of this qualitative single-case study was to develop an understanding of how mindfulness instruction strategies are being used in K-12 classrooms in Arizona, particularly as academic intervention. Recent literature discussing the use of mindfulness instruction in schools reveals psychological, behavioral, social, and physical benefits for children and adolescents, but the measured effects of mindfulness instruction as an academic intervention are inconsistent, ranging from negligible to noteworthy. The Monitoring and Acceptance Theory from Lindsay and Creswell (2017) provide the theoretical foundation for the present study. Focusing on school-based mindfulness instruction, the present study investigated how a sample of K-12 teachers who have been trained in the use mindfulness instruction strategies incorporate those strategies in their classrooms, particularly as academic intervention. The sources of data included semi-structured interviews, a focus group discussion, and field observation notes. Data analysis procedures included transcription, data cleaning, and a multi-step framework analysis. Key themes extracted from data analysis covered frequency of use, duration of use, in-classroom strategies, home practice strategies, schoolwide strategies, considerations for use, experiences, and student responses. Participants described how mindfulness affects student learning by eliminating stress, improving focus and engagement, and heightening metacognition. In addition to listing the indirect effects of mindfulness instruction strategies on academic success (such as by improving student behaviors), participants described direct positive effects on academic performance. [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.]