Bullying in workplaces creates great suffering for the victims and causes major consequences for the workplace atmosphere and the organization. Personality in bullies and their victims is an under-investigated issue, and some researchers have suggested that not only those who bully, but also those feeling bullied may be likely to act aggressively by sharing several bully-typifying personality traits. This investigation set out to compare levels of dark personality traits (“Dark Triad”: Machiavellianism, subclinical psychopathy, and subclinical narcissism) in workplace bullies and their victims. This study comprised 172 employed people (99 women): social workers, engineers, restaurant employees, and security personnel. The study used two questionnaires, Negative Acts Questionnaire-Revised (NAQ-R) and Negative Acts Questionnaire-Perpetrators (NAQ-P) to measure who feel bullied and who can be classified as bullies. Dark Triad personality traits were measured using the Short Dark Triad (SD3) self-report measure. Bivariate correlational analyses determined that the NAQ-R was positively associated with the NAQ-P (.27). Participants who reported being the target of workplace bullying were no more likely to act aggressively themselves. The NAQ-P was positively associated with Machiavellianism (.60), subclinical psychopathy (.58) and subclinical narcissism (.54). Negligible associations (.00, .01, -.14) were found between the NAQ-R and these traits. Hierarchical regression analysis indicated that Machiavellianism and subclinical psychopathy, but not subclinical narcissism, related significantly to the NAQ-P. Machiavellianism alone accounted for 36% of the variance in bullying behaviour.