The experiences of five mentors for beginning teachers in an urban school district were examined in this study. The results of interviews with the mentors revealed that they felt a sense of increased confidence and maturity in dealing with other adults, a more clearly defined set of beliefs about teaching and curriculum, and a more objective reflection on their own teaching. The most emphatic points made by the mentors centered on their astonishment regarding the magnitude and direction of their personal and professional growth apart from their direct work with the beginning teachers. In general, this sense of professionalism was evidenced in their comments about three aspects of the program: the freedom to create one's own time schedule, the development of a broader view of the district and education as a whole, and the desire to continue professional growth. Recommendations for staff developers for use in mentoring programs and stimulating professional development are presented. (Contains 15 references.) (JPB)