Purpose: This study aimed to inquire into the educational implication of peer evaluation in PBL in relation to the evaluation system. Methods: 89 third and fourth-year medical students in PBL courses participated in this study. Descriptive statistics analysis and correlation analysis were performed. Results: Based on the results of the interviews with all the forth-year students, the feedback method of peer evaluation was modified and the peer evaluation sheet was revised. On the new peer evaluation system, the percentages of indiscriminant scores were significantly lower than those on the previous system. Peer evaluation on the new evaluation system was positively related to tutor evaluation, written examination, and quizzes. Correlations between the peer evaluation scores each units were higher than those of the tutor evaluation scores. All third-year students within the bottom ten percent on the peer evaluation score failed to successfully complete that year. Conclusion: The peer evaluation with feedback based on faculty counseling and a userfriendly evaluation sheet can be used as an effective method for assessing student performance in PBL and to screen for maladjusted students.