Background: Hospital facilities are an essential part of healthcare systems, making the assessment of their quality and sustainability pivotal. Most existing evaluation tools lack a holistic and validated approach, while predominantly excluding the built environment. The Italian hospital evaluation tool SustHealth v2 addresses the shortcoming of existing applications through its structured and more integrated approach; there is the need for further testing it. Methods: The study aims to test for the first time in an international case study the multicriteria assessment tool previously developed and validated. The tool assesses social, environmental, and organisational qualities in hospitals with an online survey containing 199 closed questions sent to German hospitals. A total of 14 full replies have been collected and the resulting data analysed through descriptive statistics and heat maps identifying patterns in ownership and size. Results: Within the sample, higher scores are reported in Social Quality, while lower in Environmental and Organisational Quality. Respondents performed well in the sustainability dimensions of health promotion, waste management, and patient safety. Improvements can be achieved in energy management, facility management, and technological innovation criteria. Private hospitals slightly outperform both public and non-profit clinics. The findings presented in this study suggest a non-linear relationship between sustainability and hospital size since the highest scores were obtained by either small or large facilities. Conclusion: The study highlighted strengths and limitation of SustHealth v2. Further testing and comparison are encouraged in different context.