Prior research examining peer influences on adolescent alcohol, cigarette, and marijuana use has primarily focused on the positive associations that peer substance use and offers have with adolescent use. Consequently, such research has often emphasized the negative influences of peers. This study, however, operationalizes peer influence through best‐friend communication against substance use and examines whether it indirectly protects against substance use by promoting anti–substance use norms. Structural equation modeling was utilized with longitudinal survey data from 277 Latino and 350 non‐Latino white 6th–8th‐grade‐students. For Latino and non‐Latino white students, best‐friend communication was indirectly related to alcohol and cigarette use through norms. Best‐friend communication also was indirectly related to marijuana use, but only for non‐Latino white students and for male students.