Narcissism, Machiavellianism and psychopathy are commonly referred to as the Dark Triad of personality. In the current study, we examined the structure of the Dark Triad measured by the Polish version of the Short Dark Triad (SD3). The study was conducted with 1012 individuals in Poland. The analyses were performed in four steps: (1) the external validity of the SD3 was tested to provide evidence that SD3 is a valid measure of the three dark traits; (2) the structural validity of the SD3 was tested using competing models in confirmatory factor analyses; (3) the structure of narcissism was tested; and (4) the combined bifactor model of Machiavellianism and psychopathy was tested. The results support the differentiation of the Dark Triad into a Dark Dyad (Machiavellianism and psychopathy) and narcissism, which can be used in further theoretical work and new operationalization of the Dark Triad.