This study examined trajectories of substance use among Black and White young men (N=983) from adolescence to emerging adulthood using two-part growth curve analysis. Controlling for parental socioeconomic status, Blacks were significantly less likely to use alcohol and hard drugs than Whites at age 17 and drank significantly fewer drinks. The alcohol prevalence gap between Blacks and Whites further increased over time. Blacks in the older cohort had higher growth in the frequency of alcohol use than Whites. Blacks and Whites did not differ in prevalence of marijuana use, although Blacks in the younger cohort reported higher growth in prevalence and higher frequency at age 17. Different prevention approaches may be needed to reduce substance use among Blacks and Whites.