AbstractThe present study focused on the relationship between trait mindfulness and the outcome component of performance, evaluated with objective indicators. In particular, four objective performance indicators were studied: accuracy, reaction time, variability in reaction times, and detection of unexpected stimuli. Because attention and awareness have been described as core components of mindfulness, and previous research suggests that mindfulness is associated with improved attention skills, this study predicted that trait mindfulness would be positively related to objective indicators of high performance (accuracy, detection of unexpected stimuli) and negatively related to objective indicators of low performance (reaction time, variability in reaction time), on an attention task. Moreover, the study predicted that the relationship between trait mindfulness and objective performance would be modulated by task complexity. University students (139) completed mindfulness, intelligence, and personality questionnaires and completed an adapted Stroop task (Stroop, 1935) in E-prime 2 software. To test our hypotheses, we performed hierarchical multiple regression analyses in SPSS. Our results revealed that trait mindfulness is not related to objective indicators of performance in an attention task, except for the detection of unexpected stimuli. Going further with our analyses, we also confirmed the important role of intelligence in performance outcomes. Finally, task complexity was not playing a moderator role in the relationship between mindfulness and objective performance. Our research contributes to the literature on mindfulness and objective performance, providing empirical evidence for the relationship between trait mindfulness and the detection of unexpected stimuli. Study limitations and avenues for future research are discussed.