This research focuses on immigration and youthful illegalities in the Toronto area, one of the world's most ethnically diverse global cities. While current research documents a negative relationship between crime and immigration, there is little attention to individual level mechanisms that explain the paths through which immigrant youth refrain from illegalities. Through a study of two cohorts of adolescents across two generations (1976, 1999), we elaborate a process model that is generic over both generations, and in which measures of bonds to parents and schools, commitments to education, and dispositions of risk aversity mediate youth involvement in illegalities. By focusing on a period when non European immigration to Toronto increased dramatically, we then identify a compositional effect through which the more recent cohort is engaged in fewer illegalities. (Contains 3 figures, 5 tables and 5 notes.)