The present study was designed with the purpose of contributing to the existing scientific literature about the presence of Dark Tetrad personality traits--Machiavellianism, psychopathy, narcissism, and sadism--in aggressors and victims of school bullying, also taking into account the possible gender differences in both roles. The results, obtained by means of the Two-Way Multivariate Analysis of Variance, with a sample of participants made up of 2977 adolescents and aged between 11 and 17, indicated that adolescents with a higher participation in bullying behaviors and those that are highly victimized, obtained higher scores in the four Dark Tetrad traits. By gender, boys displayed higher scores in sadism, both in the bullying and victimization model. In addition, two interactions between victimization and gender were identified: Victimization was associated with higher comparative levels of Machiavellianism and narcissism in boys than in girls. These results suggest the need to include the study of these components of personality and gender in the understanding, prevention, and intervention in school bullying situations among adolescents.