This study examined TESL degree candidates' initial impressions of trustworthiness in a supervisor. As an antecedent of self-disclosure, trust plays a critical role in supervision that encourages reflection and awareness of personal beliefs and values. In an exploration of how a supervisor's communication style can affect teachers' perceptions of trust, 266 participants from 22 TESL programs viewed videotaped segments of conferences in which the supervisors' nonverbal behaviors of either dominance or affiliation were manipulated. The teachers then rated the supervisors on three separate scales: the Individualized Trust Scale (ITS) and a communicative competency measure consisting of appropriateness and effectiveness scales. As hypothesized, supervisors with an affiliative style scored higher on the ITS than those who displayed nonverbal behaviors of dominance. Teachers also rated affiliation as being more appropriate and effective than dominance. Moreover, positive associations were found between trust and teachers' ratings of appropriateness and effectiveness. These results have implications for preparing L2 teacher educators as well as teacher learners to engage in productive supervision.