Research has consistently shown that adolescent smoking is related to friends' smoking, yet smoking in the context of adolescent peer groups (friendship cliques) has been little studied. Formal network analysis was used to identify 87 adolescent friendship cliques in a sample of 1,092 ninth graders at five schools. There was intraclique homogeneity and interclique heterogeneity in current cigarette smoking, confirming that smokers tend to be in cliques with smokers and nonsmokers tend to be with nonsmokers. Most cliques were comprised entirely or mostly of nonsmokers, suggesting that friendship cliques may contribute more to the maintenance of nonsmoking than to the onset and maintenance of smoking. Prevention and research implications are discussed.