This study assessed the diagnostic potential of the actigraph, the Continuous Performance Test, and the Matching Familiar Figures Test in diagnosing attention-deficit hyperactivity disorder (ADHD). Twenty boys previously diagnosed with ADHD and 52 controls were examined. By these measures the boys with ADHD were differentiated from the controls with sensitivity and specificity above 75%. We were able to classify ADHD into eight subtypes by combining the scores of the actigraph and the CPT: “hyperactive-impulsive”, “hyperactive-inattentive”, “impulsive-inattentive”, “hyperactive”, “impulsive”, “inattentive”, “mixed”, and “unspecified” type. These classifications may be useful in diagnosing ADHD.