Emotional labour is the effort consumed by suppressing one's own emotions to care for others effectively while also caring for oneself. Mental health nurses are required to engage in effective therapeutic interactions in emotionally-intense situations. The aim of the present integrative systematic review was to investigate the emotional labour of mental health work and how this manifested, the impacts, and the ways to mitigate these impacts. In June 2016, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology, a systematic search of the bibliographic databases was undertaken to identify relevant literature. Screening, data extraction, and synthesis were performed by three reviewers. The inclusion criteria included any original research that investigated the emotional work of mental health nurses. We identified a total of 20 papers to be included in this review. Thematic synthesis of the findings revealed three emergent themes: emotional labour and caring, emotional exhaustion, and self-protection (expressed as emotional intelligence). Emotional labour, emotional exhaustion, and emotional intelligence were considered to be intrinsically linked, where they were both the influencing factor for burnout and a contributor to attrition. The results highlighted that emotional labour could inspire the development and personal growth of emotional intelligence in mental health nurses. In light of these findings, recommendations for clinical practice were considered; they included supportive work environments, involving nurses in shared decision-making, and the provision of ongoing professional development opportunities that facilitate the development of emotional intelligence and resilience.