The authors examined the effects of heavy adolescent marijuana use on employment, marriage, and family formation and tested both dropping out of high school and adult marijuana use as potential mediators of these associations among a community sample of African Americans followed longitudinally from age 6 to age 32-33. They used propensity score matching to reduce selection bias when estimating the effects of heavy adolescent marijuana use. Logistic regression results on the sample matched on sex, and early demographic and behavioral variables showed that adolescent marijuana use has adult social behavioral consequences: Use of marijuana 20 times or more during adolescence was associated with being unemployed and unmarried in young adulthood and having children outside of marriage for both males and females. Dropping out of high school and more frequent adult marijuana use seem to be important parts of the pathway from adolescent marijuana use to negative life outcomes.