The 2-year prevention program was administered to 121 boys and girls aged 11 and 12 years. Treatment consisted of a modified version of the Life Skills Training Program. Results showed partial impact of the program on such proximal measures as social anxiety; self-esteem; influenceability; and knowledge of cigarettes, alcohol, and marijuana. Problem children in the prevention program became more assertive in comparison to control children. In addition, children in the prevention program gained more knowledge about cigarettes and marijuana. As for distal measures, children in the prevention program developed more negative attitudes toward cigarettes and marijuana from pre-test to post-test. No significant differences between prevention and control children, however, were obtained for the use of cigarettes, alcohol, and marijuana. Some links between proximal and distal variables were significant, albeit weak. Limits of child-centered prevention programs, especially with regard to at- risk children, are discussed. 65 references, 5 endnotes, and 5 tables