Introduction: Designing and constructing hospitals using a green approach leads to a reduction of energy consumption and carbon emissions, improvement of indoor and outdoor air quality. The purpose of this research is to help hospitals identify and prioritize the factors influencing the establishment of a green hospital to protect the environment. Materials and Methods: In this descriptive-analytical research, the criteria of Green Hospital were first identified by a literature review and were localized and selected by experts using the Delphi method. Then, we applied the DEMATEL method to determine the relationships and effect of factors and analytic network process methods for weighting and prioritizing factors. Results: Findings of the DEMATEL method showed that management, water use, health, treatment, and innovation are effective in establishing green hospitals. The management dimension is of the highest weight (101%) and the greatest influence (1.48) and innovation and the quality of the indoor environment with the weight 83% are in the next rank. Discussion & Conclusion: Management and its sub-criteria are the most important factors in implementing a green hospital in Fars province. As a result, the implementation of the green hospital depends on the managers' efforts. In this regard, the strategic role of managers in today's hospitals affects the environmental resources and reduces the burden of disease on society while reducing costs.