Using data from a longitudinal panel of nearly 3000 adolescents to predict current smoking among young adults, we test whether adding variables that tap prior social bonds and influences to the model eliminates race/ethnicity as a significant predictor of current smoking. At age 23, African Americans and Asians exhibited substantially lower rates of current smoking than Whites and Hispanics. Controlling for social influences during high school, particularly exposure to siblings and friends who smoked plus parental disapproval of smoking, accounted for these differences. Social bonding variables, in contrast, had a limited mediating effect. Interventions aimed at decreasing adolescent vulnerability to prosmoking influences, reducing overall levels of peer cigarette use, and helping parents better convey their disapproval of smoking should help curb young adult smoking and diminish racial/ethnic differences in tobacco use.