BACKGROUND Peer assisted learning (PAL) has been rarely investigated in surgical skills training. AIMS Describe feedback residents give peers on surgical skills with and without guidelines, determine the association between feedback and actual performance, evaluate resident satisfaction with PAL. METHOD Participants evaluated peers using a validated knot-tying checklist and provided feedback on suturing without a guideline. Feedback comments were coded by type and an expert scored performance of each participant. Residents completed a satisfaction questionnaire. RESULTS Comments were generally specific. Feedback was twice as likely with the use of a guideline. Specific feedback correlated significantly with expert knot-tying score but not suturing score. Most participants felt peer feedback was helpful and were motivated to practice surgical skills after PAL sessions. CONCLUSIONS Surgical residents can provide high quality specific feedback to peers on surgical skills using performance guidelines. Further exploration of effective PAL methodology in surgical skills laboratory training is needed.