In a two-year investigation of cigarette smoking incidence in a population of Minnesota adolescents, the perceived smoking behavior of friends at baseline was a strong predictor of smoking onset. Additional predictors included: siblings' smoking behavior, parents' education level, and seven psychosocial scales including independence and rebelliousness. Smoking prevention strategies which teach youth to cope with social influences are well founded. Results also indicate that younger adolescents may yet be dissuaded from beginning smoking by knowledge of the health consequences of smoking.