Mentoring contributes to prospective principals' growth, easing their transition from the role of teacher to that of administrator. This article reports findings from a study aimed at examining the determinant factors affecting the mentor-mentee relationship in a uniquely designed principal preparation program in New York City. The study population comprised 18 prospective principals and 6 acting principals serving as mentors. Data were collected via semistructured individual interviews and written reports. Data analysis reveals three main categories as determinants of a productive mentor-mentee relationship: personal characteristics, professional discourse, and time and frequency of communication. Findings are analyzed and coupled with recommendations for creating successful and productive mentor-mentee relationships.