The purpose of this quantitative study was to determine if an intern in a principal preparation program had a better experience during their internship if they were able to select their field-based mentor as opposed to being assigned a mentor by the administrators of the program. The literature addressed the current role of the principal and discussed the principal preparation programs that educate and prepare them for leadership. In particular, the internship phase of principal preparation programs was reviewed with respect to the framework of adult learning theory and current principal leadership standards. The internship phase has been shown to be the key component of a principal preparation program, and the intern-mentor relationship has been shown to be the critical factor for a successful field experience. An online survey with 14 Likert statements was given to graduates of a principal preparation program and was used to measure the effectiveness of the intern-mentor relationship based on five mentoring domains and the interns' satisfaction level with their mentor. Using descriptive statistics, the results of the study found that interns who were able to select their mentor had a more favorable perception of their mentor's effectiveness and were more satisfied with their relationship. Implications for future research and future practice are presented for universities that administer principal preparation programs. [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.]