PurposeThe purpose of this research is to examine the influence of the Dark Triad personality traits (Machiavellianism, narcissism and psychopathy) on consumers’ purchase intentions for counterfeit luxury products via the mediating effect of moral disengagement, drawing on moral disengagement theory. Furthermore, descriptive norms are tested as a moderators of the mediated relationships between the Dark Triad personality traits and purchase intentions via moral disengagement based on trait activation theory.Design/methodology/approachTo test the hypotheses, a survey design is employed to gather primary data from 205 consumers. The final data are analysed using partial least squares structural equation modelling.FindingsThis study finds that moral disengagement mediates the relationships between (1) Machiavellianism, (2) psychopathy and purchase intentions. Descriptive norms are found to moderate the indirect effect of moral disengagement between psychopathy and purchase intentions.Originality/valueDark Triad personality traits are linked to various unethical behaviours. However, no studies have explored how Dark Triad personality traits influence consumers’ purchase intentions for counterfeit luxury products. This study sheds light on how consumers with high Dark Triad personality traits are more likely to be morally disengaged, thereby leading to purchase intentions for counterfeit luxury products, drawing on moral disengagement theory. Furthermore, this study demonstrates descriptive norms as the boundary condition for the mediating relationship between Dark Triad personality traits and purchase intentions via moral disengagement, drawing on trait activation theory. The findings can be used to formulate better strategies to counteract the phenomenon of counterfeit luxury consumption.