This phenomenological study explored the perspectives of nine OB/GYN residents who experienced a formal mentoring relationship during a portion of their residency years. The purpose of the study was to determine the necessary knowledge for the graduate medical education mentor to be effective as mentor. The mentor relationship is a complex sociological relationship and this study focused on the resident perspective throughout. The major findings of the study were that the following should be developed into a mentor development curriculum (a) the benefits to the resident and the residency program; (b) that there are six roles that the mentor plays; and (c) that administrative oversight is essential to maintaining effective mentoring relationships. Hopefully, this study will encourage reflection by graduate medical education stakeholders as they pursue further research as recommended and as they develop tools for measuring the effectiveness of medical resident mentoring relationships.