Marijuana is the most widely used illegal drug, and the use of marijuana has been linked to a wide array of maladaptive outcomes. As a result, there is great interest in identifying the factors that are associated with the use of marijuana and with desistance from marijuana. The current study employed a life-course framework to examine the factors associated with early onset of marijuana use, with the use of marijuana during adolescence, and with desistance from marijuana use in young adulthood. Analysis of data drawn from the National Longitudinal Study of Adolescent Health revealed that low self-control and delinquent peers were predictive of marijuana use, an early onset of marijuana use, and desistance from marijuana use. In addition, the models revealed that marriage increased the odds of desistance from marijuana use, even after controlling for delinquent peers, low self-control, and selection effects. The implications of our findings are noted. (Contains 3 tables and 1 note.)