Aim. The present study contributes to our understanding of how to curb burnout among hospital staff over time. We extend existing research by examining the mediating role of mission valence in the link between transformational leadership and burnout. Method. Self-administered questionnaire data from employees in a Canadian general hospital (N = 185) were analyzed using a time-lagged research design to examine whether transformational leaders can increase employees’ attraction to the organization’s mission (i.e., mission valence), and in turn alleviate long term burnout. Findings. Structural equation modelling analysis demonstrated that transformational leadership (time 1) was negatively related to the burnout components of emotional exhaustion and depersonalization (time 2). Further, the results showed that mission valence mediated these relationships. Conclusion. The study findings are important for managers and professionals as they identify transformational leadership as a potent strategy to alleviate employee burnout and clarify the process through which this is achieved, namely, by increasing mission valence. Originality. To date, surprisingly little research has explored how transformational leadership influences followers’ burnout. To address this issue, the present study examined the role of transformational leadership on staff burnout through the mechanism of increasing mission valence. Understanding how to mitigate burnout is particularly critical in health care organizations given that burnout not only negatively impacts employee wellbeing but also the wellbeing and quality of care provided to patients.