Impairment analyses indicated substantial neuropsychological impairment in the offender and psychiatric groups, especially on measures of executive function and verbal capacities. The neuropsychology of the prefrontal cortex and of Attention Deficit Hyperactivity Disorder and Conduct Disorder were reviewed in the context of the present findings, and supported a working hypothesis that the executive deficits and behavioral disinhibition of offenders represent heterotypic continuities of brain dysfunction among some children with disruptive behavior disorders. An expanded Halstead-Reitan Neuropsychological Test Battery supplemented by several other neuropsychological tests emphasizing verbal and memory abilities and the Wechsler Intelligence Scales were administered to a group of adult offenders, normal controls and acute psychiatric patients. Full descriptive statistics for all neuropsychological measures were reported. Implications for potential research, the potential neuropsychology of offenders, and the early identification and remediation of high risk children are discussed. Data were collected from a test group consisting of 584 adult North American Caucasian males serving prison terms in excess of 2 years and admitted to a maximum security psychiatric penitentiary, 132 normal controls, and 494 acute psychiatric patients in a Canadian facility; subjects were between 18 and 44 years of age. Table, references