The purpose of this study was to shed light on mentor teachers' perceptions of their roles and responsibilities and to contrast their understandings with a normative view of mentoring (Goldsberry, 1998; Hawkey, 1997). We hypothesized that the mentor teachers' perceptions would likely differ from established conceptions of this construct, a difference that has significant implications for mentor preparation and university collaboration. Participants, 264 teachers who were serving as mentors to pre-service teachers, were asked open-ended questions designed to allow the mentors to describe the ways in which they envisioned their role. Follow-up telephone interviews were conducted with 34 randomly selected mentor teachers to further determine the relative value they placed on different aspects of mentoring. The results of this research confirm that mentoring is a complex construct and that the perceptions held by mentors may be influenced by the kinds and quality of mentoring experiences they have had. Implications for the appropriate selection, preparation, and support of mentor teachers are discussed. (Contains 7 tables.)