Recent epidemiological studies suggest that both social anxiety and attention deficit hyperactivity disorder (ADHD) in childhood might predict levels of delinquent behavior in adolescence. The current study prospectively examines the influence of social phobia and ADHD symptom scale scores on the correlation in conduct disorder symptom scale scores over time. An epidemiologically selected sample of 776 young people living in Upstate New York received DSM-based psychiatric assessments in 1983, 1985, and 1992 using structured interviews. Correlations among conduct disorder scales over time were examined as a function of social phobia and ADHD ratings. Individuals with low scores on social phobia scales or high scores on ADHD scales exhibited the highest correlation in conduct disorder symptom scales over time. There was also a suggestion that low scores on social phobia scales predicted later risk for conduct disorder. Low scores on social phobia symptom scales or high scores on ADHD scales predict stronger across-time correlations in conduct disorder symptom scales. Various cognitive or biological factors might account for these moderating effects on conduct problems.