National estimates of delinquency cases for 2010 are based on analyses of individual case records from more than 2,200 courts and aggregate court-level data on cases from nearly 200 additional courts. Together, these courts had jurisdiction over 82 percent of the U.S. juvenile population in 2010. National estimates of petitioned status offense cases for 2010 are based on case records from just over 2,000 courts and court-level data from 136 additional courts. These courts cover 74 percent of the juvenile population. Two chapters of the report present national estimates of delinquency cases handled by the juvenile courts in 2010 and analyze caseload trends since 1985. One of the chapters describes the volume and rate of delinquency cases, demographic characteristics of the juveniles involved (age, gender, and race), and offenses charged. The other chapter traces the flow of delinquency cases from referral to court through court processing, examining each decision point (detention, intake decision, adjudication decision, and judicial disposition). Data are presented by demographic characteristics and offense. Together, these two chapters provide a detailed national portrait of delinquency cases. A third chapter presents national estimates of status offense cases formally processed by the juvenile courts in 2010. It presents data on demographic characteristics, offenses charged, and case processing. An appendix explains the statistical procedure used to generate these estimates. The report’s format combines tables, figures, and text. A detailed index of tables and figures is provided.