Across 4 years, 87 teaching assistants (TAs) completed measures designed to assess personal efficacy, teacher efficacy, and liking for teaching before (pretest) and after (posttest) a weeklong training program. Paired sample t tests revealed a significant increase in personal efficacy and liking for teaching, a significant positive correlation between personal efficacy and desire for teaching (at pretest), and a significant positive association among all 3 variables at posttest. Personal efficacy predicted a significant amount of variance in liking for teaching at pretest (24%) and posttest (28%). A social-cognitive framework explains how components of the training program contribute to increased TA personal efficacy and enjoyment of teaching. (Contains 2 notes.)