Research supports the validity of the dimensional approach to psychopathy in both children and adults. The occurrence of severe aggressive and antisocial behavior in combination with callous-unemotional traits (CU traits) designates a group of children that is particularly at risk to develop psychopathy. However, most studies did not investigate the role of the remaining psychopathy dimensions (i.e. narcissism and impulsivity) in comparison. The present text reviews the newest developments in the dimensional study of psychopathy in relation to cognition, behavior and affect in clinical and detained child and adolescent samples. Findings support the role of the callous-unemotional dimension (CU traits) in the development of psychopathy. Additionally, they also underscore the importance of the narcissistic and impulsive dimensions for the understanding of psychopathy in children and adolescents and for the identification of different psychopathy profiles. Understanding differential correlates of the underlying dimensions of psychopathy is an important step in formulating interventions for those most at risk.