Background Over 80 countries have now signed up to the COP26 Health Programme—a World Health Organization (WHO)-led initiative on climate change and health—of which 45 countries have committed to reaching net zero emissions before 2050. Efforts to reduce healthcare’s carbon footprint raise conceptual, ethical and practical challenges for efficient and fair resource allocation. This study investigates how civil servants leading the development and implementation of national net zero healthcare strategies conceptualise the responsibility of health systems to cut emissions and describe potential trade-offs along the way. Methods We undertook 11 online, semi-structured qualitative research interviews between September 2022 – May 2023 with civil servants leading national net zero healthcare strategies. The interview guide explored three main areas: responsibility for emissions, priority setting and international perspectives. Interviews were coded and analysed the data using Malterud’s systematic text condensation (STC). Results Four main themes emerged: obligation to act, leadership, governance, and prioritization. Participants described that the healthcare system should take responsibility for its entire carbon footprint, including harms inflicted beyond national borders. We also found indications of synergistic, multi-scalar health leadership—clinical, civil service, and political—helping to accelerate the net zero healthcare agenda. Participants generally rejected the notion of direct “tradeoffs” between efforts to reduce emissions and patient care, emphasising ways net zero healthcare can leverage societal health improvements more broadly. These empirical findings inform the emerging literature exploring how health systems should account for their environmental impacts. Conclusion Our findings highlight the sincerity of ambitions to deliver net zero healthcare and uncertainties on how to get there. Further work characterising the types of constraints and trade-offs policy-makers face on the path to net zero healthcare systems, including examples of how these have been overcome, could help integrate climate concerns into healthcare decision-making and resource allocation processes.