Graduate teaching assistants (TAs) receive little to no formal training in pedagogy before entering the classroom. Such deficiencies may contribute to increase anxiety and poor self-efficacy for TAs, potentially hindering opportunities to train future faculty. We tested the effects of a previously established, low investment, method of TA training through making and receiving peer-evaluations on TA self-efficacy compared to performing self-assessments and reflection of teaching experiences in three introductory biology courses at a large, Mid-western university. While peer-evaluations did not affect quantitative measures of self-efficacy, we did observe greater increases in self-efficacy among TAs with more experience. We suggest that future studies on the effects of peer-evaluations may be most effective when conducted by experienced TAs.