Statement of Purpose and Method of Study: This quantitative study aimed to investigate the influence of principal preparation on the leadership behaviors of elementary school principals who supervise, support, and evaluate prekindergarten teachers in Mississippi public schools. Specifically, the researcher sought to determine if statistically significant differences exist in the self-reported mean instructional leadership domain scores of principals who supervise, support, and evaluate the developmentally appropriate practices (DAP) of prekindergarten teachers based on demographic data and preparation factors. The researcher identified three constructs from existing literature that comprise principal preparation: prior teaching experiences, principal preparation programs, and job-embedded professional development. The researcher used t-tests and a series of ANOVAs to compare principals' mean instructional leadership domain scores (MILDS) based on preparation factors and demographic data. Data from 54 principals who supervise, support, and evaluate prekindergarten teachers was included in the analysis. Findings and Conclusions: Three major conclusions can be drawn from this study. First, the amount of job-embedded professional development that principals engage in matters. Findings from this study reveal significant differences across all three domains of instructional leadership based on reported hours of professional development. Second, the race of a principal makes a significant difference in how the principals rate their level of engagement in instructional leadership activities associated with promoting a positive school climate. Finally, when managing the school's instructional program, longevity in the principalship makes a difference. [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.]