In the past decades, the use of indices and indicators to report on the environmental performance of organisations has increased exponentially. However, the available studies did not address the topic of obtaining indicators that show the environmental behaviour of the health sector. The main objective of this research, therefore, was aimed at the calculation of environmental efficiency indices in the hospital sector, taking a regional hospital as a case study and considering the environmental aspects identified during the development of its healthcare activity in 2019. The results obtained provided information on the potential environmental impacts triggered by every aspect of the operation of a hospital in the course of its activities that focus on patient care. The results demonstrated that the aspects related to transportation of patients, workers, and materials had the greatest impact on the global environmental indices we calculated. For the environmental efficiency indices of hospital activities, the most significant environmental aspects were materials consumption and waste generation.