This study examined the perceptions of experienced teachers who had taken on formal roles as mentor teachers. Case studies were developed for each of 10 participants, of whom 7 were neophyte mentors. Each mentor was interviewed four times throughout the school year, while their mentees were each interviewed twice. Mentors were also observed in the classroom. Results emphasized the idiosyncratic nature of the mentor/mentee relationship, and found the district/school culture surrounding the mentor program to have a significant influence on the relationship. Since the evolution of mentor/mentee relationships is found to be highly unpredictable, it is argued that those designing such programs should emphasize creating the optimal context for positive relationships rather than attempting to mandate specific dimensions of the relationship. It is also suggested that more structured mentor programs serve to establish a more clear understanding of each participant's mission, goals, and role, as well as lending an institutional validity to these roles. The importance of training for mentor teachers in specific skills such as active listening, clinical supervision, and adult development is also stressed. (Contains 43 references.) (PB)