School principal's practices are affected by many factors on a daily basis. Various factors affecting their practice are invisible to the eye and silent by the spoken word. However, the problem exists that there is a lack of research identifying the experiences of practicing principals regarding teacher self-efficacy. Furthermore, there is not sufficient research distinguishing how principal leadership practices are affected by teacher self-efficacy. It was assumed by the researcher that the principals' knowledge of teacher self- efficacy is lacking, therefore, creating a void in his or her comprehension of the role of the principal and further establishing the possibility of an existing phenomenon. The purpose of this study was to examine the experiences of practicing principals regarding teacher self-efficacy by means of interviews, participant journaling, and researcher observations. Additionally, the purpose of this study was to determine, using an in-depth review, of how the principal experience is affected by teacher self-efficacy. The design of the study followed a phenomenological inquiry approach of eight school principals and the effect that the teacher self efficacy experience has on their practice. Analysis of their lived experiences surfaced rich textural and structural themes of their practice and the effects of teacher self efficacy. This inquiry also resulted in a more complete and meaningful understanding of principal practice in relation to the tensions and demands experienced in the pragmatic world of school. [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.]