Evidence clearly demonstrates that youth who frequently use or abuse drugs are more likely to engage in chronic delinquent behavior than do other adolescents. While some distinguishing factors are evident in the etiology of serious delinquency and drug abuse related to gender, drug used, type of delinquency, and severity of the behavior, some precursors appear to be common to both. These risk factors include early and frequent antisocial behavior, parent and sibling drug use and criminality, poor and inconsistent family management practices, family conflict, family social deprivation, and school failure and low commitment to education. Others include peer influences, attitudes and beliefs indicating a lack of social bonding with conventional society, lack of community attachment, community disorganization, and mobility. A variety of constitutional and personality factors also have been associated with both drug abuse and delinquency, such as depressed nervous system arousal, sensation-seeking, low verbal ability rebelliousness, alienation, and hyperactivity. Evidence suggests that greater attention be given to prevention approaches addressing these multiple common risk factors and to the coordination of services targeting youth exhibiting serious antisocial behavior. Promising prevention, control, and treatment are identified. 6 tables and approximately 300 references.