Objectives <p>The present study used latent profile analysis to examine how mindfulness and Dark Tetrad traits co-occur within individuals and relate to antisocial behavior.</p> Method <p>A sample of 6643 Chinese undergraduates completed measures of four Dark Tetrad dimensions (Machiavellianism, narcissism, psychopathy, and sadism) and five facets of trait mindfulness (observing, describing, acting with awareness, non-judging, non-reactivity).</p> Results <p>Four distinct profiles emerged: (1) Unmindful Offenders (24.1%; high dark traits, low mindfulness), (2) Normative Majority (33.8%; average on both dimensions), (3) Adaptive Narcissists (18.9%; high narcissism, high mindfulness), and (4) Detached Predators (23.2%; high dark traits, selective mindfulness in observing and non-reactivity). Profiles differed significantly in antisocial behavior, <i>F</i>(3, 6639) = 650.42, <i>p</i> &lt; 0.001, <i>η</i>² = 0.227. Detached Predators reported the highest levels of antisocial behavior, suggesting that selective attentional skills without ethical restraint may facilitate calculated misconduct. In contrast, Adaptive Narcissists’ strong non-judging and awareness skills were linked to the lowest antisocial tendencies.</p> Conclusions <p>These findings underscore the moral neutrality of trait mindfulness: its effects depend on how facets are distributed in relation to dark personality traits. Implications for personalized interventions and ethical safeguards in mindfulness training are discussed.</p> Preregistration <p>This study is not preregistered.</p>