Executive dysfunction in those high on traits of psychopathy has often been reported, with many disagreements as to the nature of the dysfunction. We aimed to see if tests of planning and rule acquisition/adherence would discriminate those high on psychopathic traits. A battery of executive function tests (Tower of London, Brixton Spatial Anticipation, and Hayling Sentence Completion Tasks) was given to 28 British male prisoners. Psychopathy was measured using the Psychopathy Checklist-Revised. High psychopathy was related to reduced planning in the Tower of London Test and poor rule-adherence on the Brixton Test. Other tests of executive function were not related to psychopathy. The results appear supportive of the notion that function of the orbitofrontal cortex (OFC) is dysfunctional in psychopathy whilst that of the dorsolateral prefrontal cortex (DLPFC) is normal and suggest that impulsivity in those high on psychopathy traits impedes planning and rule following. We suggest the adapted Tower of London Test and the Brixton Test could be useful objective measures of this type of impulsivity in offenders which could help identify key treatment goals.