Moral distress has been identified as an occupational hazard for clinicians caring for vulnerable populations. The aim of this systematic review was (i) to summarize the literature reporting on prevalence of, and factors related to, moral distress among nurses within acute mental health settings, and (ii) to examine the efficacy of interventions designed to address moral distress among nurses within this clinical setting. A comprehensive literature search was conducted in October 2022 utilizing Nursing & Allied Health, Embase, CINAHL, PsychInfo, and (...) PubMed databases to identify eligible studies published in English from January 2000 to October 2022. Ten studies met inclusion criteria. Four quantitative studies assessed moral distress among nurses in acute mental health settings and examined relationships between moral distress and other psychological and work-related variables. Six qualitative studies explored the phenomenon of moral distress as experienced by nurses working in acute mental health settings. The quantitative studies assessed moral distress using the Moral Distress Scale for Psychiatric Nurses (MDS-P) or the Work-Related Moral Stress Questionnaire. These studies identified relationships between moral distress and emotional exhaustion, depersonalization, cynicism, poorer job satisfaction, less sense of coherence, poorer moral climate, and less experience of moral support. Qualitative studies revealed factors associated with moral distress, including lack of action, poor conduct by colleagues, time pressures, professional, policy and legal implications, aggression, and patient safety. No interventions targeting moral distress among nurses in acute mental health settings were identified. Overall, this review identified that moral distress is prevalent among nurses working in acute mental health settings and is associated with poorer outcomes for nurses, patients, and organizations. Research is urgently needed to develop and test evidence-based interventions to address moral distress among mental health nurses and to evaluate individual and system-level intervention effects on nurses, clinical care, and patient outcomes. (shrink)