This paper tests predictions of continuity and change in antisocial behavior over time as derived from population heterogeneity and life-course perspectives. These predictions are assessed with respect to a rarely studied form of delinquent/criminal behavior, cocaine use during the late-teenage and young adult years. We first examine the extent to which differential propensities toward antisocial behavior can be detected in a nationally representative sample of youth aged 14-16 in 1979. Based on self-reported delinquent and criminal activities in late adolescense, traditional cross-sectional latent-class analysis identifies three groups of antisocial/rebellious respondents and a group of non-offenders. We then follow these groups into early adulthood, examining age trajectories of cocaine usage between 1984 and 1998. Latent-class trajectory models identify clusters of respondents who show similar age trajectories of cocaine use over time and provide parameter estimates that predict membership in those clusters. In support of the population heterogeneity perspective, we find that antisocial/rebellious youth have higher probabilities of cocaine use throughout early adulthood than non-of-fending youth. There is, however, much variation in drug use patterns among the groups as they aged. In support of a life-course perspective, we find that social ties to schools, families, religion, and the labor market help differentiate youth who refrain from, maintain, or desist from using cocaine through early adulthood.