This report examines risk and protective factors associated with adolescent tobacco involvement. Of interest are family contexts, peers, and individual covariates. Participants were 399 youth, parents, and a close-in-age sibling. Of the youth, 150 initiated use early (7th, 8th, or 9th grade), 82 later (10th or 11th grade), and 167 abstained. Employing Cox's Proportional Hazard Models, youth at greater risk for tobacco involvement were characterized by male gender, higher deviant values, lower school performance, and friends and/or siblings who use tobacco. Results for early users are fairly consistent with the complete sample. For youth who begin in late adolescence, sibling and peer tobacco use are not significant covariates, whereas risk factors include low conventional values. Results are consistent with earlier discriminant function analyses that identified school performance and friends who are users as predictors of involvement, and extend that research by separately examining covariates of tobacco use during early and late adolescence and by examining risk factors associated with friends who are users. Identification of similar and distinct factors for early and late initiators highlights the need for specific strategies for prevention. (EMK)