This study investigates how the undergraduate Learning Assistant (LA) experience affects teachers' first year of teaching. The LA Program provides interested science majors with the opportunity to explore teaching through weekly teaching responsibilities, an introduction to physics education research, and a learning community within the university. Some of these LAs are recruited to secondary science teacher certification programs. We hypothesized that the LA experience would enhance the teaching practices of the LAs who ultimately become teachers. To test this hypothesis, LAs were compared to a matched sample of teachers who completed the same teacher certification program as the LAs but did not have the LA "treatment." LAs and "non-LAs" were compared through interviews, classroom observations, artifact packages, and observations made with Reformed Teacher Observation Protocol (RTOP) collected within the first year of teaching. Some differences were found; these findings and their implications are discussed.