Individuals with early-emerging conduct problems are likely to become parents who expose their children to considerable adversity. The current study tested the specificity of and alternative explanations for this trajectory. The sample included 246 members of a prospective, 30-year cohort study and their 3-year-old children. Parents who had a history of conduct disorder were specifically at elevated risk for socioeconomic disadvantage and relationship violence, but suboptimal parenting and offspring temperament problems were common to parents with any history of disorder. Recurrent disorder, comorbidity, and adversity in the family of origin did not fully account for these findings. The cumulative consequences of early-onset conduct disorder and assortative mating for antisocial behavior may explain the long-term effects of conduct disorder on young adult functioning.