Although racial and ethnic minorities are more likely to be involved with the criminal justice system than whites in the U.S.A., critical scientific gaps exist in our understanding of the relationship between the criminal justice system and the persistence of racial/ethnic health disparities. Individuals engaged with the criminal justice system are at risk for poor health outcomes. Furthermore, criminal justice involvement may have direct or indirect effects on health and health care. Racial/ethnic health disparities may be exacerbated or mitigated at several stages of the criminal justice system. Understanding and addressing the health of individuals involved in the criminal justice system is one component of a comprehensive strategy to reduce population health disparities and improve the health of our urban communities.