Sixteen-channel topographic brain mapping of electroencephalograms of 25 right-handed males, 9-12 years of age, with attention-deficit-hyperactivity disorder revealed increased theta (4-7.75 Hz) and decreased beta 1 (12.75-21 Hz) when compared with 27 controls matched for age and grade level. The differences were greater when patients were tested for reading and drawing skills, but were decreased when they were at rest during visual fixation. Although the differences in patients with attention-deficit-hyperactivity disorder were generalized, increased theta was more prominent in frontal regions, while beta 1 was significantly decreased in temporal regions. Principal component analysis was used to combine the variables into 2 components which accounted for 82% of the total variance. A discriminant function analysis using these components was able to predict group membership for attention-deficit-hyperactivity disorder patients 80% of the time and 74% for controls. These findings support the use of topographic electroencephalography for further elucidation of the neurophysiology of attention-deficit-hyperactivity disorder.