This article summarizes current knowledge concerning child abuse in the United States. It discusses major approaches to assess the incidence and prevalence of child abuse, including the national family violence surveys (NFVS), national incidence studies (NIS), and national child abuse and neglect data system (NCANDS) surveys. It mentions the estimates of abuse rates provided by the different data sources, apparent changes in prevalence rates over time, and possible explanations of these changes. This article considers ethnic differences in rates of child abuse and data relating to these differences. It provides an overview of competing definitions of child abuse and the major theories for its occurrence. It concludes with the description of the criminal justice system's response to the problem and implications of research for public policy.