Proclamations about the problem of juvenile delinquency typically cite a body of facts about youth crime or facts about juvenile delinquency. Statistics on juvenile delinquency are influenced by a wide range of factors other than the behavior of juveniles. Whether an event is recorded as a crime is a product of both public and police action and the interaction between the two. In addition, whether suspects become statistics as criminals or juvenile delinquents depends on such contingencies as offense committed, offense history, complainant preference, the way suspects and complainants interact with police, and organization and operational practices of police departments. Police and court statistics indicate that crime and juvenile delinquency increased rapidly from the 1960s through the mid-1970s but rates may have been much higher before the collection of statistics nationwide. For several decades, juveniles accounted for a growing proportion of arrests in national crime data but their contribution appeared to stabilize or decline for some offense categories beginning in the mid-1970s. Rates of crime and juvenile delinquency appear to be high in areas experiencing population changes and transitions and in cities as compared to rural settings, but differences between rural and urban settings seem to be declining. Males are more likely than females to appear in arrest and court statistics, young people between 10 and 17 years of age are disproportionately represented in arrest statistics, blacks have the highest overall arrest rates, and lower class young people disproportionately contribute to police and court statistics. Official statistics indicate relatively stable rates of arrest and referral for drug offenses, and studies of the processing of lower class young people suggest legal criteria (offense seriousness and prior record) explain disproportionate representations in police and court statistics. Moreover, females may receive either preferential or harsher treatment than males, depending on the offense and the stage of processing. The value of using statistics to study juvenile delinquency is discussed. 59 references and 10 figures