The Swiss healthcare system is known to be one of the most polluting in the world on a per capita basis. This study focuses on Geneva and investigates the carbon footprint of the hospital sub-sector, including the Geneva University Hospitals, the private clinics, the ambulance services, and the homecare institution. I collected raw data on their activities, transformed into equivalent kg of CO₂ with appropriate emission factors, to finally calculate the carbon footprint of this sub-sector. Hospitals are the main greenhouse gas emitter, accounting for 48% of the healthcare system’s emission, the homecare institution represents only 3% and the ambulance services less than 1%. The most prominent emission items are medicines and medical devices by far, followed by heating, transport, and catering. To conclude, we propose direct and indirect measures, either with an immediate impact or implementing systemic changes. This study with an estimated carbon footprint and the proposed action levers hope to serve as a basis for ambitious emission reduction policies to curb the CO₂ emissions.