One hundred junior high schools were randomly selected and assigned, 20 per condition, and some 5,000 Grade 6 youth with approximately the same number of females and males, recruited to cohort which participated in intervention and evaluation through the end of Grade 10. The junior high curriculum was delivered to all volunteers in each intervention school in Grades 6, 7, and 8. All participants were tested five times: midway through Grade 6 before the intervention began, and at the end of Grades 7, 8, 9 and 10. The primary endpoint was self-reported smoking status at the ends of Grades 8 and 10, 2 1/2 and 4 1/2 years after the intervention began. The validity of smoking reports were enhanced with collection of breath carbon monoxide samples from all subjects at all test points.