Purpose: The purpose of this study was to develop and evaluate a school-based peer leader centered smoking prevention program. Methods: Non-equivalent control group with a pre/post-test design was used. Students (n=174) in two boys' junior high schools located inD city, Korea participated with 85 being selected for the experimental group and 89 for the control group. Five sessions were given to theexperimental group and a 50 minute lecture to the control group. Knowledge, attitude, non-smoking intention, and non-smoking efficacywere measured for the both experimental and control group at two weeks before the program and one month after the program was completed. Data were analyzed using χ2-test, Fisher’s exact test, independent t-test and paired t-test with the SPSS 21.0 program. Results:The experimental group showed higher overall knowledge, negative attitude toward smoking, and higher non-smoking intention and efficacy. After receiving the school based peer leader centered smoking prevention program scores for attitude toward smoking and nonsmokingefficacy increased in the experimental group were higher than in the control group. Conclusion: The school-based peer leadercentered smoking prevention program needs longitudinal evaluation, but from this study, there is an indication that this program can beused with junior high school students and effectively change students’ attitude toward smoking and promote non-smoking efficacy.