Objective: The authors examined the utility of the computerized Cambridge Neuropsychological Test Automated Battery (CANTAB) to evaluate executive functioning deficits in children with ADHD. Method: Participants were unmedicated children and adolescents with (n = 107) and without (n = 45) Diagnostic and Statistical Manual of Mental Disorders (4th ed.) ADHD. The authors administered the CANTAB Eclipse battery, which comprises specific tasks shown to be deficient in individuals with ADHD. Results: With the exception of the affective go/no-go total omissions, ADHD participants were significantly more impaired on all other subtests of the CANTAB in comparison with controls. Effect sizes for individual CANTAB tests were largely in the medium range with the largest effect sizes seen in spatial working memory total and between errors. Conclusion: These CANTAB results are highly congruent with those reported in studies using traditional neuropsychological testing batteries, supporting the utility of the CANTAB to assess neuropsychological deficits in children with ADHD in clinical and research settings. (J. of Att. Dis. 2012; XX(X) 1-XX)