Scholars have argued that combining supervision and evaluation is a conflict of interest that will damage the coaching process. Peer assistance and review (PAR) is an approach to the supervision and evaluation of teachers that runs counter to this argument, as the coach charged with providing professional support to a new or struggling veteran teacher also plays a formal role in that teacher's summative personnel evaluation. This article presents data from a study of one urban school district in California as it implemented a PAR program, asking: (1) To what degree do PAR mentees trust their coaches, who conduct both formative and summative assessments? (2) How do PAR mentees who do not trust their coaches differ from those who do? Mentees' trust in their coaches was a point and a half higher than their lack of trust in their coaches, as self-reported on a 4-point Likert scale. Those mentees who did not report a high degree of trust in their coaches were low-performing mentees.