Research has consistently revealed that measures of psychopathy and psychopathic personality traits represent some of the most consistent predictors of violent criminal involvement. As a result, there has been a considerable amount of interest in trying to identify the various etiological factors related to psychopathy. The current study builds on this existing body of literature by examining the association between neuropsychological deficits and psychopathic personality traits. Data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care were analyzed. Adolescent psychopathic personality traits were measured with a 15-item scale drawn from the Youth Psychopathic Traits Inventory (YPI), whereas neuropsychological functioning was assessed with a number of standardized tests of cognitive skills. Analyses revealed that neuropsychological deficits were significantly related to psychopathy measures across all four measurement phases. Neuropsychological deficits also predicted scoring in the top 5% of psychopathic personality traits.