We analyzed the mediating effect of mindfulness on the relationship between dark personality traits (Machiavellianism, narcissism, and psychopathy) and the frustration and satisfaction of basic psychological needs. The research sample comprised 642 nonclinical working adults. The following measurement tools were used: the dark triad of personality, the Basic Psychological Need Satisfaction and Frustration Scale, and the Mindful Attention Awareness Scale. Dispositional mindfulness fully mediated the relationship between narcissism and basic psychological need frustration. The frustrated participants who were less mindful were also more narcissistic. If the participants were only more frustrated but not less mindful, they did not show a higher level of narcissism. There was a significant relationship between psychopathy and basic psychological need frustration, which was partially mediated by mindfulness (12% of the total effect). There was no relation between Machiavellianism and mindfulness. Mindfulness did not mediate the relationship between Machiavellianism and the basic psychological need frustration/satisfaction. There was no significant relationship between mindfulness and the satisfaction of basic psychological needs. The authors discussed the protective effect of dispositional mindfulness in the context of frustrated basic psychological needs and narcissism, psychopathy and the possibilities of developing dispositional mindfulness.