CATCH provides multiethnic cohort data from third to eighth grades from four US geographic regions. This study examined smoking behaviors and predictors from fifth and eighth grades by ethnicity, gender, and geographic location through self-report data obtained from the cohort (N = 3,654). Overall, eighth grade prevalence for ever smoked was about 44%, 30-day prevalence was about 20%, 7-day prevalence 13.3%, and daily prevalence 7.4%. Prevalence was similar for Caucasians (21.5%) and Latinos (21.6%) and lowest for African Americans (13.1%). The 30-day prevalence for smokeless tobacco was higher for boys than for girls (9.8% vs 5.1%). Tobacco use by parents, siblings, and friends, and easy accessibility in the home in fifth grade, were significant predictors for smoking in eighth grade. Results did not differ by race, gender, or geographic location. The strongest correlate of smoking in eighth grade was having a best friend who smoked. Intention not to smoke in fifth grade predicted nonsmoking in eighth grade. Predictor strength across ethnic groups in different geographic regions was impressive. The social environment of young people continues to be an important instigator of smoking onset. The connection between intention and behavior over time suggests students' intentions not to smoke reflect decision-making at an early age.