Objectives: To contribute to the limited evidence base supporting mindfulness in the workplace, beyond the current wellbeing-related outcomes, this study investigated the relationship between self-reported mindfulness and perceptions of team-member exchange (TMX). Emotion regulation was included as a mediator in this relationship. Method: A total of 496 workers employed within teams across a range of industries completed a self-report questionnaire. Results: Mindfulness was significantly and positively related to TMX, and this relationship was mediated by emotion regulation. Specifically, high level of dispositional mindfulness was related to reappraisal and TMX, and low level of mindfulness was related to suppression and low TMX. Conclusions: These findings support the role of mindfulness and emotion regulation in interpersonal functioning and provide evidence of its role in co-worker relationships. As one of the first studies to investigate the benefits of mindfulness for co-worker relationships, this provides direction for further research and some grounding for mindfulness being incorporated into interventions to address teambuilding and workplace conflict.cognitive reappraisal, co-worker relationships, emotion regulation, expressive suppression, mindfulness, team-member exchange