Peer mentors in learning communities for first-year students aid new students in their transition to college. However, little is known about how these peer mentors address concerning student behaviors, particularly those that may suggest a psychiatric/psychological disability. This research addressed the issue by asking peer mentors how they were trained and how they attended to concerning behaviors in their learning community groups. Findings from this qualitative study, based on individual interviews with 11 peer mentors in one learning community, centered around the impact of peer mentor training on the mentors, their role in observing and addressing behaviors, and their observations about the ways learning community students responded to peers demonstrating concerning behaviors. Recommendations for the use and training of peer mentors are identified.