Purpose: The purpose of this study was to examine professional leadership experiences of college deans of education with formal and informal mentoring in the course of their career progression at 4-year nonprofit private colleges and universities in California. Methodology: Using a mixed-methods approach that emphasized the qualitative data paradigm, the study design was descriptive and ex post facto. The data collection was sequential where the quantitative data were collected using electronic surveys with selected deans whose institutions met the established study criteria, followed by interviews with willing participants. The survey instrument assessed the helpfulness and duration of mentoring, positions held in the process, and demographic background of participants. The interviews reflected the role of mentoring in leadership development and preparation prior to the deanship. Findings: Examination of qualitative and quantitative data indicated that education deans had exposure to leadership roles in committees, served as department chairs and in other administrative roles. Scholarship development, institutional perspective, managing personnel, and finances were skills resulting from the mentoring experience. Deans who participated in both formal and informal mentoring leaned toward informal mentoring as the most helpful experience. Traditional and peer/lateral were also identified as beneficial and the most helpful type of mentoring in preparing for the deanship. Conclusions: The experiences college deans encountered indicate that informal, traditional, and peer mentoring were their preferred venue for leadership identification, preparation, and development. Deans had minimal experience with team mentoring and mentoring circles in the course of career progression. Recommendations: Further research is needed to explore other types of mentoring that incorporate a systematic approach in preparing future academic leaders. It is recommended that the study be replicated with a greater number of college deans at other institutions. Other research to be conducted involves exploring the cultural differences between the ethnicities deans and its effectiveness among the various types of mentoring. [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.]