Based on self-determination and conservation of resources theories, the aim of this study was to examine the mediating role of psychological capital in the relationship between trait mindfulness and employee well-being. 210 nurses voluntarily participated in the survey study. The data were analyzed via Process Macro. Findings suggested that trait mindfulness predicts employee well-being and psychological capital had a mediating role in this relationship. Theoretical implications were discussed and practical suggestions were made for managers and specialists.