Graduate teaching associates (GTAs) play a vital role as instructors at many universities but often are not confident in their ability to perform their job-related duties. Based on Bandura's (1997) theory of self-efficacy, this project examined a teacher-training program for GTAs and assessed its outcomes. Our results revealed that GTAs reported being more likely to choose prosocial behavioral alternation techniques to manage students after training. They also reported significantly higher self-efficacy across three instructional areas: management, student involvement, and instructional strategies. Finally, GTAs expressed a belief that they could count on more mentoring support than they believed they had prior to training. Only the perceptions of peer support remained unchanged. (Contains 2 tables.)