Towards environmentally sustainable healthcare: using quality improvement to deliver a net zero NHS

East London NHS Foundation Trust uses quality improvement as its approach to solving complex problems. This article uses a case study methodology to describe how the trust's programme of sustainability used quality improvement at both systemic and local levels to support the organisation to reduce direct greenhouse gas emissions by 40% by 2025 and indirect emissions by 40% by 2036. Using quality improvement in a structured way enabled staff and service users to consider their contribution to sustainability and develop, test and measure ideas that were within their control. This led to an organisational reduction in gas emissions of 37% and CO₂ emissions by 14% in winter months. At a local level, three case studies showcase the accomplishments of teams who successfully reduced medication waste by 66.2 kg CO₂e per year, reduced spending on single-use plastics by 54% and lowered CO₂ emissions by 10798 kg per year through the return of walking aids. Supporting structures for the programme included active and visible participation from senior stakeholders, with service users and carers involved at both strategic and operational levels, and tracking data over time. Future work should focus on creating a change package of ideas to serve as a blueprint to scale up these initiatives across the organisation.