The Denver Youth Survey gathered information from 1,527 males and females ages 7, 9, 11, 13, and 15 at the start of the study and from one of their parents. The research used data from personal interviews conducted during 1988-92. The research constructed measures of three family characteristics: family adversity, parental crime involvement, and parenting as indicated by parental monitoring and supervision. Results revealed that parenting was directly and indirectly related to delinquency and could contribute to both increases and decreases in the chance of a child's involvement in delinquent behavior. Having poor parental monitoring and supervision or having parents who were or had been involved with the law increased the likelihood of delinquent involvement. In contrast, parents who provided at least moderate supervision reduced this risk, especially for youths ages 13-16 years. Children who were difficult as indicated by factors such as hyperactivity or impulsiveness were also more likely than others to be involved in delinquency. Delinquent peers also influenced delinquency; better parenting reduced levels of involvement with delinquent peers. Low levels of monitoring or its absence, rather than high levels of monitoring, appeared to make a difference. Finally, the stronger findings for youths than for children suggested that parent training for parents of teenagers as well as children may deserve greater attention as a delinquency prevention strategy. Tables, figure, and 6 references