We reported previously on the success of an innovative approach to cigarette smoking prevention in seventh-grade students. The present report describes a 3-year follow-up of three schools and 1081 students initially involved in the research program. The curriculum emphasizes the short-term influences which affect smoking in youth, particularly social and peer influences. In the school which received this curriculum from like-aged peer leaders, the incidence of smoking remained low compared to that in a control school. Those who did smoke in this school consumed significantly fewer cigarettes. In the school where the curriculum was adult taught, smoking rates were initially lower but rose in the later years, ultimately differing little from those in the control school. Reported smoking behavior was confirmed by saliva thiocyanate measurement in all students. Cigarette smoking behavior appears significantly inhibited by a peer-taught curriculum and that effect is retained for several years after the education program.