This study compared a six-session peer-led smoking intervention program for high school-age youth to the same program led by adults. Ninety-three students participated in the study and were divided into peer-led, adult-led, and control groups. Number of cigarettes smoked was assessed by self-report through pretest, posttest and one-month follow-up measures. Self-efficacy was measured post-and follow-up. Student feedback regarding the helpfulness of program components was also assessed. There was a significant difference in the number of cigarettes smoked by students in both peer-led and adult-led groups when compared to the control group (p = .0001). Smoking reduction continued to take place in both treatment groups at the one-month follow-up measure. Those students who were exposed to fewer smoking individuals in their daily lives were able to maintain a reduction in smoking when measured one month after completion of the program.