Moral injury may be experienced when a person perpetrates, witnesses or fails to prevent an act that conflicts with their moral values and beliefs. The concept of moral injury has its origins in the context of military personnel encountering ethically challenging decisions during armed conflict. The term has been applied to healthcare and moral injury is increasingly acknowledged to be a challenge for healthcare professionals. Nurses across all specialties and settings are frequently required to make or witness ethically challenging decisions about patient care. The coronavirus disease 2019 (COVID-19) pandemic has increased nurses’ risk of sustaining moral injury. This article discusses the manifestations of moral injury and its associated risk factors, including the effects of the COVID-19 pandemic. It also outlines various strategies that can be used to mitigate and/or prevent moral injury in nurses.