The program called Project ALERT (Adolescent Learning Experiences in Resistance Training) was tested with seventh and eighth graders in 30 California and Oregon schools in urban, suburban, and rural communities. Nine of the schools had minority populations of 50 percent or more. Each school was randomly assigned to one of three experimental conditions: sessions conducted by teachers only, sessions conducted by teachers assisted by older teen leaders, and a comparison group that did not receive the Project ALERT curriculum. Findings showed that Project ALERT effectively prevented or reduced cigarette and marijuana use among the young adolescents. The program was equally effective in schools with substantial minority populations and in predominantly white schools. However, the early gains in alcohol prevention had eroded by the time the students reached eighth grade. In addition, previously confirmed cigarette smokers actually smoked more after being involved in the program. Results showed the importance of booster sessions in the eighth grade and the need for a different strategy for confirmed smokers. Figures, tables, footnotes, illustrations, and 98 references.