Aim of the study The main question of this study is whether there is a specific relation between Dark Triad personality traits and proactive and reactive aggression in adolescents between 14 and 19 years old. Design The present study is a cross-sectional correlational study. Methods There were 62 participants in the study, these participants were aged between 14 and 19 years and were all students of a high school in Maastricht. Both boys (n = 22) and girls (n = 40) participated in the study. To answer the main question, the participants of the study completed two questionnaires. First, they completed the Dirty Dozen for Youths (DD-Y), a questionnaire to measure the Dark Triad personality traits. Second, they completed the Child Rating scale for Aggression (CRA), a questionnaire to measure proactive and reactive aggression. Results There was no significant difference between boys and girls on the aggression questionnaire, but there was a significant difference between boys and girls on the subscales psychopathy and Machiavellianism. There was no difference between the participants from different educational levels and there was no relation between age and the different subscales. To find out if the personality trait of the Dark Triad were unique predictors of general aggression, reactive aggression and proactive aggression, a multiple regression analysis was carried out. It was found that Machiavellianism is a unique predictor for general aggression, proactive aggression and reactive aggression and that psychopathy is a unique predictor for aggression in general. Conclusion Because Machiavellianism and psychopathy have proven to be unique predictors of aggression and Machiavellianism is even a specific predictor of proactive and reactive aggression, an intervention to prevent/reduce the development of aggression may be designed. In this way, it can be prevented that the development of the child is disturbed by aggressive behavior. Further research into the role of Machiavellianism in the development of aggression is recommended.