Abstract. The aim of this research was to examine the structure of the Dark Triad and Tetrad traits by answering the question whether a person-centered or a variable-centered approach is more suitable for their description, or its combination. Moreover, we examined whether the inclusion of sadism into the dark traits constellation would change the results. On a sample of 404 participants, both short and full-length measures of the Dark Triad were used, while sadism was assessed via Short Sadistic Impulse Scale. The results of the factor mixture analysis showed that the variable-centered approach is better at describing the Dark Triad, but the inclusion of sadism resulted in qualitatively different latent profiles, suggesting that the person-centered approach could serve in describing the Dark Tetrad. Inclusion of sadism led to the isolation of higher Dark Tetrad-sadism profile in both short and full-length measures and this profile showed the higher risk behaviors and interpersonal problems. Other isolated profiles could be interpreted as lower and higher Dark Tetrad profiles, with some specificities. Results showed that inclusion of sadism contributed to the isolation of profile more prone to sadism, but also to isolation of other profiles, suggesting that it could change the relations among dark traits.