Results indicated that 61 percent of youth reported lifetime offending while 40 percent reported active offending. Active property crime was reported more frequently than active violent crime, 32 percent and 25 percent respectively. The findings indicated that two key factors served as underlying causes of all forms of active offending: (1) anti-social behavior and attitudes, and (2) impulsivity. Other factors that were closely related to offending behavior included: (1) negative school experiences (females); (2) undesirable behavior by family members (males); (3) poor relationship with family (male); (4) negative perceptions of neighborhood (property crime); and (5) drug-related attitudes and behavior (15-16 year olds). The findings suggest that offending among Welsh youth is a multi-faceted problem with a wide range of contributing factors. As such, a comprehensive, multi-agency approach targeting different risk factors for different segments of the population is desirable. Future research should offer cross-sectional comparisons and longitudinal investigations on the development of risk factor influence over an extended time period. An opportunity sample of 3,088 students aged 11 through 16 years was drawn from 22 secondary schools in 14 of 22 local authority areas in Wales. Participants completed a survey measuring their self-reported engagement in delinquency via a computer-assisted self-interviewing process. Data were analyzed using factor analysis followed by logistic regression analysis. Tables, figure, references, appendix