The purpose of this study is to investigate the correspondence between neuropsychological tests and brain electrical activity mapping in adolescents with Conduct Disorder (CD). The study seeks to identify underlying brain abnormalities and to identify more precisely left/right and anterior/posterior differences in this population. Although such information is thought to provide valuable data for diagnosis and treatment (Lahey et al., 1993; Shapiro & Hynd, 1993) few studies directly address these issues. Subjects for this investigation include 10 males, ages 12-18 at a residential treatment center in Texas. All subjects meet DSM-IV diagnostic criteria for CD and none has neurological abnormalities nor major psychoses. Subjects' neuropsychological test results were compared to their topographic brain maps. The latter includes EEG, auditory cognitive evoked potentials, visual evoked potentials, and P300, all processed by Fast Fourier Transformation. Analyses of neuropsychological test results suggest indicators of organicity most frequently involved tests associated with left hemisphere functioning. Analyses of electrophysiology data revealed QEEG and EP abnormalities manifest as anterior/posterior and interhemispheric differences. Both sets of data suggest that underlying brain abnormalities characterize this group of adolescents with Conduct Disorder. Implications for diagnosis and treatment will be discussed.