This paper provides a 5-year replication-extension of a previous 1-year follow-up study of the same sample of southern California alternative high school youth. Demographic, behavioral, psychosocial, and emerging adult function predictors of adolescent self-initiated smoking cessation were investigated. Based on the first (1-year) prospective study and this follow-up, one may speculate that smoking cessation programs for adolescents should include counteraction of problem-prone attitudes, assistance with job aspirations and information about drug-free workplaces, motivation to quit strategies, and assistance with overcoming withdrawal symptoms.