The twelfth edition of the publication «Key data on Swiss hospitals» contains like the previous version data for each Swiss hospital. Article 59a of the Health Insurance Act, which came into force on 1st January 2016 (previously article 22a of the Health Insurance Act), together with Article 31 of the Health Insurance Ordinance, provide the legal basis for this publication. Data are based on the Hospital Statistics and the Medical Statistics of Hospitals for 2016 from the Federal Statistical Office (FSO). They give an overview of the hospitals structure, patients, benefits, offer/supply, personnel and financial situation as well as the illness average severity of acute in-patients.