The paper examines a number of theoretical concepts such as social disorganization, social learning theory, and posits others to understand the urban reality for aboriginal populations and, from that, regional variation in over-representation. It also analyzes socioeconomic and criminal justice data from the nine cities chosen for analysis, and compares aboriginal and non-aboriginal population characteristics of the cities. The paper focuses primarily on the contribution large urban areas make to the over-representation phenomenon, and suggests that it is critical to explore the genesis of urban disadvantage, particularly for populations migrating from reserves. The central issue is the concentration of poor, single parent, and poorly educated aboriginal people in the inner core of large cities. Collective efficacy and social capital theories would suggest that it is social and economic organization and related structures of advantage or disadvantage that affect people's lives and influence crime and disorder. These factors also influence who stays and who leaves reserves, and who fails and who succeeds in cities. Tables, notes, references