Rapid urbanization globally threatens to increase the risk to mental health and requires a rethinking of the relationship between urban poverty and mental health. The aim of this article is to reveal the cyclic nature of this relationship: Concentrated urban poverty cultivates mental illness, while the resulting mental illness reinforces poverty. The authors used theories about social disorganization and crime to explore the mechanisms through which the urban environment can contribute to mental health problems. They present some data on crime, substance abuse, and social control to support their claim that mental illness reinforces poverty. The authors argue that, to interrupt this cycle and improve outcomes, social workers and policymakers must work together to implement a comprehensive mental health care system that emphasizes prevention, reaches young people, crosses traditional health care provision boundaries, and involves the entire community to break this cycle and improve the outcomes of those living in urban poverty.