Previous research has demonstrated that mindfulness helps reduce symptoms of work stress but research has yet to clarify "whether" and "how" mindfulness is linked to work engagement. Using self-determination theory we hypothesize that mindfulness is positively related to work engagement and that this relationship can be better understood through authentic functioning. We collected survey data on these variables in the context of six mindfulness trainings at three points in time: before the training, directly after the training, and four months after training. We examined the relationships between mindfulness, authentic functioning, and work engagement, both statically (cross-sectionally) and dynamically as they change over training. Results show that authentic functioning mediates the relationship between mindfulness and work engagement, partially for the static relationship and fully for the dynamic relationship. We discuss how these findings further clarify the role of mindfulness in the workplace and highlight the implications for the literature on authentic functioning and work engagement. (Contains 2 figures and 1 table.)