This study investigated the differences between trained Clinical Faculty (CF) and untrained cooperating teachers (CTs) in terms of their sense of self-efficacy for mentoring student teachers; ratings of student teachers’ performance; new teachers’ perceived competence; and new teachers’ perceived impact on K-12 student learning and development. The findings reveal that trained Clinical Faculty tended to have greater self-efficacy for mentoring. The findings showed that greater accuracy in assessing student teacher performance may result in stronger actual performance of student teachers placed with CF as compared to those placed with untrained CTs, as evidenced by comparably higher evaluations by university supervisors.