• Psychopathy, Machiavellianism and narcissism make up the Dark Triad of personality • These Dark Triad traits were proven to be related to numerous antisocial behaviors • Such research on the Dark Triad has mainly focused on adolescent (online) samples • We tested the effect of these traits on offending in a representative adult sample • Of the three, only psychopathy and Machiavellianism were related to adult offending The present study investigates to what extent the three key concepts from the Dark Triad Theory can explain individual differences in adult offending. Data were collected through a cross-sectional survey amongst a representative sample of 1587 adults, living in Ghent, Belgium (M age = 48.06, 51.4% female). Negative binomial regression analyses are run and show that Machiavellianism and psychopathy have strong independent effects on adult offending, independent of age, sex and immigrant background.