The purpose of this study is to examine the similarities between mentor teachers' espoused theories and theories-in-use. Semi-structured interviews were conducted with 16 mentor teachers to investigate their perceived mentoring roles prior to the placement. Their seven pre-service teachers were also interviewed at the end of the practicum to explore their ideas and evaluation of their mentors' mentoring practices. The findings suggest that 14 mentor teachers did put into practice their ideas regarding their roles. However, only two mentor teachers appeared to act against their espoused theories. Implications for practice are discussed.