The purpose of this mixed methods study was to describe relationships between stress, burnout, and perfectionism and provide the first empirical documentation of the prevalence and perceived role of perfectionism among music educators. I collected quantitative data on perceived stress, stress appraisal, burnout, and perfectionism in a national sample of preK-12 music educators. I used a transcendental phenomenological approach to describe the essence of the lived experience of perfectionism for preK-12 school music educators. Qualitative participants each completed a written narrative and semi-structured interview. Five research questions guided this study: (a) Which, if any, demographic variables predict perfectionism in K-12 music teachers in the United States? (b)Is there a relationship between perfectionism and stress appraisal in K-12 music teachers in the United States? (c) Is there a relationship between perfectionism and burnout in K-12 music teachers in the United States? (d) What is the lived experience of perfectionism for K-12 music teachers in the United States? (e) In what ways do the survey and phenomenology data align with one another? Several demographic variables may predict perfectionism in preK-12 music teachers in the United States. Music teachers in both the quantitative survey and qualitative interview results became less perfectionistic in multiple dimensions of perfectionism as they got older and as they gained years of experience. There was a moderate to strong relationship between each dimension of perfectionism and perceived stress as well as each dimension of perfectionism and each dimension of stress appraisal in preK-12 music teachers in the United States. There appeared to be a strong relationship between perfectionistic concern and the emotional exhaustion dimension of burnout as well as a moderate relationship between perfectionistic striving and socially prescribed perfectionism and the emotional exhaustion dimension of burnout. Participants? lived experiences with perfectionism were dichotomous. Perfectionism could serve as a motivating, positive force as participants strove for excellence with reasonable and sustainable practices; however, perfectionism could also lead participants into maladaptive, unsustainable habits and attitudes that developed from unreasonable internally or externally imposed expectations that typically led to stress and exhaustion. Implications for music teacher educators and practicing music teachers include the importance of content-specific mentors for novice music teachers as well as suggestions for cognitive-behavioral strategies to address perfectionistic thoughts and behaviors. [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.]