Young offender populations typically display high rates of substance use pathology and mental health concerns, however, little is known regarding how these factors relate to dynamic risk factors for reoffending (criminogenic needs) among young offenders. The present study investigated a Canadian sample of 186 youth charged with serious/violent offenses on measures of psychopathology, substance abuse, risk, and recidivism. Significant relationships were found between measures of substance abuse with most indices of the Youth Level of Service/Case Management Inventory (YLS/CMI), a validated risk assessment tool designed to assess criminogenic risk and need. Furthermore, measures of substance abuse predicted general, violent, and nonviolent recidivism for both youth and adult outcomes to varying degrees. Youth with disruptive behavior disorders, comorbid substance use concerns with another disorder (dual diagnosis), or with two or more disorders evidenced more serious criminogenic need profiles, whereas mood, anxiety, and cognitive disorders were unrelated to criminogenic risk. With the exception of conduct disorder and substance use pathology, mental health concerns tended not to be related to recidivism. The implications of these findings in terms of assessing risk and providing treatment services for young offenders is discussed in relation to the risk-need responsivity (RNR) model of effective correctional intervention.