Introduction: The environmental impact of haemodialysis is very high. Institutional activity in this sense is important, even in the production of references. Voluntary environmental management systems (EMS), environmental management and auditing systems (EMAS) and the International Organization for Standardization standards (ISO 14001) are important tools for environmental protection, together with legislation, taxation and tax benefits. Objectives: To determine the degree of implementation of EMS in hospital units and outpatient haemodialysis in the Spanish National Health System to provide a group of reference centres in environmental management in this healthcare activity. Methods: Development of a list by autonomous communities showing hospital and outpatient dialysis units using an EMAS and/or ISO 14001 in 2012–2013. The sources of information were the Spanish National Catalogue of Hospitals, Spanish Registry of Healthcare Certification and Accreditation, European and regional EMAS records, world ISO registrations, dialysis centre lists from scientific societies and patients, responses from accredited entities in Spain for environmental certification and the institutional website of each haemodialysis centre identified. Results: Of the 210 hospitals with a dialysis unit, 53 (25%) have the ISO 14001 and 15 of these also have an EMAS. This constitutes 30% of all hospital dialysis chairs in Spain: 1,291 (of 4,298). Only 11 outpatient clinics are recorded, all with the ISO 14001. Discussion: There is no official documentation of the implementation of EMS in dialysis units. Making this list provides an approach to the situation, with special reference to haemodialysis because of its significant environmental impact.