Examined the effects of comorbid externalising disorders (i.e., attention-deficit/hyperactivity disorder [ADHD], oppositional defiant disorder [ODD], conduct disorder [CD]) on the long-term outcome (7.4 years) of individuals treated for anxiety disorders as youth. Ninety-four anxiety-disordered children (aged 8-13) were provided with a 16-session manual-based cognitive behavioural treatment (CBT). Assessments were completed at pretreatment, posttreatment, 1-year posttreatment (see Kendall, et al., 1997) and for 88 of the original 94 subjects at 7.4-years posttreatment (see Kendall, Safford, Flannery-Schroeder, & Webb, in press). At pretreatment, all participants received principal anxiety diagnoses (generalised anxiety disorder, separation anxiety disorder, social phobia). Nineteen had comorbid externalising disorders (11 ADHD, 7 ODD and 1 CD). These 19 subjects were matched on age (within an average of 3 months), gender and race with 19 previously treated youths who were not comorbid with an externalising disorder. Examining parent- and child-reports, respectively, comparable rates of comorbid versus non-comorbid cases were free of their principal anxiety disorder at the 7.4-year follow-up on all dependent measures. Parents of anxiety-disordered children with a comorbid externalising disorder reported higher levels of child externalising behaviour than did parents of anxiety-disordered children without comorbidity. Comorbid children reported greater self-efficacy in coping with anxiety-provoking situations than did non-comorbid children. Thus, it appears that overall anxiety-disordered children with and without comorbid externalising disorders showed comparable improvements following CBT.