Objective: To describe the late adolescent drug use outcomes from a relatively large, community-identified sample of children with attention-deficit/hyperactivity disorder (ADHD) who have been assessed longitudinally from childhood through late adolescence. Method: Adolescent drug use outcomes were compared between ADHD-only (n = 27), ADHD-externalizing (mostly oppositional defiant disorder) (n = 82), and normal control (n = 91) groups. Results: The ADHD-externalizing group revealed significantly worse drug use outcomes (drug use frequency and substance use disorders) compared to the other two groups, and the ADHD-only group showed outcomes comparable to the community control group. Conclusions: ADHD without a comorbid externalizing disorder is not associated with an increased risk of drug abuse. ADHD with a comorbid externalizing disorder, primarily oppositional defiant disorder, is associated with an elevated risk of drug use, particularly with respect to marijuana and tobacco involvement. (Contains 1 figure and 3 tables.)