The purpose of this study was to examine if a relationship existed between the self-efficacy and grit of selected principals; the differences in self-efficacy and grit among the principals who did and did not participate in a principal development program; and the differences in self-efficacy, grit, and persistence in the job role of the selected principals with varying years of experience. The study focused on Texas public school districts in the Principal Pipeline program and included 101 principal responses. Data collection occurred via an electronic survey. In this quantitative study, a correlational research design was the means used to address Research Question 1. A multivariate analysis of variance commenced to analyze the data related to the research questions. The findings of this study showed a direct, significant relationship between principal self-efficacy and grit. Additionally, the principals who participated in an additional professional development program separate from their districts had slightly higher self-efficacy and grit scores than those who did not. The findings showed that the principals had the highest self-efficacy within their first 3 years and the lowest self-efficacy between 4 and 10 years. The principals did not have an upward trend in self-efficacy until their 11th year in the role. Regarding self-efficacy and grit for different demographics, the study found that gender had no influence on principal self-efficacy and grit. The high school principals had the lowest mean scores for self-efficacy, while junior high and middle school principals had the highest scores. Elementary principals had the lowest level of grit, while high school principals had the highest. The most significant finding of self-efficacy and grit related to the age demographic. The study's data suggest that as principals mature, their levels of self-efficacy and grit increase. The recommendations for future research include examining how to include self-efficacy and grit in principal development programs via qualitative studies of principals in the Principal Pipeline. Another recommendation is to explore the proven practices for increasing principal self-efficacy and grit. [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.]