While medical audit in infection control today is one important element in the quality assurance of health care, environmental auditing, approved in 1993 by the Council of the European Communities for the industrial sector, so far has not been used as a tool to control and reduce environmental pollution caused by medical care. The aim of this study was to investigate whether environmental auditing according to the European Eco-Management and Audit Scheme (EMAS) can be implemented in hospitals as a process of improvement in protection of the environment. In a prior publication the methodological issues and the organizational steps that had to be taken were described. An environmental review of the activities of the Freiburg University Hospital and an ecoanalysis of the input and output were performed. The results of this analysis, published in an environmental report, provide a fundamental data set for the consumption of energy, water, materials, and the burdens of major pollutants and waste. Regarding the organizational structure of the hospital, the first steps towards an integrating environmental management system as demanded by EMAS could be taken. Beside supporting advantages,e.g., improvement of environmental safety, public image and staff contentment, and potential economic benefits such as less cost to be paid for energy and water consumption, there are important restrictions of environmental auditing in hospitals. Examples are the lack of basic environmental data, staff motivation (especially of physicians), cooperation of the organizational substructures, and funds for prefinancing urgently needed improvements in ecology. Based on the study findings, a textbook on environmental auditing in hospitals, including checklists covering all important environmental objectives, has been published to support hospitals in their efforts to achieve an optimized and sustainable practice of providing health care.