We evaluated the convergence of CBCL scales with the diagnosis of ADHD and comorbid disorders in 133 ADHD and 118 normal control boys, aged 6-17 years old. We evaluated the strength of association between each CBCL scale and structured-interview derived diagnoses with Total Predictive Value (TPV) and the odds-ratio (OR). Excellent convergence was found between the CBCL Attention Problems scale with the diagnosis of ADHD, between the Delinquent Behavior scale and the diagnosis of CD, and between the Anxiety/Depression scale and the diagnoses of Anxiety Disorders. These findings indicate that the CBCL could serve as a rapid and useful screening instrument to identify comorbid and non-comorbid cases of ADHD.