BackgroundBetween 2001 and 2014, British military nurses served in Afghanistan caring for both service personnel and local nationals of all ages. However, there have been few research studies assessing the psychological impact of delivering nursing care in a war zone hospital. PurposeThe purpose of the study was to explore the challenges and psychological stressors facing military nurses in undertaking their operational role. MethodsA constructivist grounded theory was used. Semi-structured interviews were conducted with 18 British Armed Forces nurses at Camp Bastion Hospital, Afghanistan, in June to July 2013. DiscussionMilitary nurses faced prolonged periods of caring for seriously injured polytrauma casualties of all ages, and there were associated distressing psychological effects and prolonged periods of adjustment on returning home. Caring for children was a particular concern. The factors that caused stress, both on deployment and returning home, along with measures to address these issues such as time for rest and exercise, can change rapidly in response to the dynamic flux in clinical intensity common within the deployable environment. ConclusionClinical training, a good command structure, the requirement for rest, recuperation, exercise, and diet were important in reducing psychological stress within a war zone. No formal debriefing model was advocated for clinical staff who appear to want to discuss traumatic incidents as a group, and this may have contributed to stigma and nurses feeling isolated. On returning home, military nurses reported being disconnected from the civilian wards and departments. The study raised the question of who cares for the carers, as participants reported a perception that others felt that they should be able to cope without any emotional issues. It is envisioned that the results are transferable internationally to nurses from other armed forces and will raise awareness with civilian colleagues.