Objective: ED staff are subject to many stressors, but there are few descriptions of collective approaches to enhancing wellness in this setting. We aim to describe a programme developed to address these issues at department level, to report the feasibility and sustainability of the programme, and its impact on staff. Methods: The oneED programme was developed and delivered in a tertiary ED. The programme included a 1 day mindfulness workshop, followed by ongoing mindfulness activities embedded in clinical areas over the subsequent 12 months. A mixed-methods evaluation of the programme was conducted, which included quantitative validated psychological tools to measure anxiety, depression and emotional exhaustion, and pragmatic evaluation using surveys of participants and iterative appreciative inquiry. Results: Eighty staff members attended the mindfulness workshop; 66 from ED. Following the workshop, understanding and frequency of mindfulness practice increased significantly in 47% of participants. Free-text survey results demonstrated that staff found the programme to be acceptable (80% survey participants) and of perceived value to themselves (50%) and the ED (60%). Appreciative inquiry led to modification of the programme: the 4 min pause is now conducted weekly rather than daily, the pause consists of a variety of activities, and group activities are made more overtly optional. Conclusion: A departmental wellness programme embedding mindfulness practice is feasible and sustainable. Potential for success is enhanced by an approach that is open to modification according to each institution's culture.