This essay breaks new ground in exploring the tensions in female nursing during the Second World War as the mental health needs of the injured were increasingly acknowledged. Advances in weaponry and transportation meant that the Second World War was a truly global war with mobile troops and enhanced capacity to maim and kill. A critical mass of female nursing sisters was posted to provide care for physical trauma, yet the nature of this uniquely modern war also required nurses to provide psychological support for troops readying for return to action. Most nursing sisters of the British Army had little or no mental health training, but there were trained male mental health nurses available. Publications of broadcasts by the Matron-in-Chief of the British Army Nursing Service detail the belief that the female nurse was the officer in charge of the ward when the patients had physical needs. However, that the nursing sister held this position when the patients' requirements were of a psychological nature was at times tested and contested. Through personal testimony and contemporary accounts in the nursing and medical press, this essay investigates how female nursing staff negotiated their position as the expert by the psychologically damaged combatants' bedside. The essay identifies the resourcefulness of nurses to ensure access to all patient groups and also their determination to move the boundaries of their professional work to support soldiers in need.