The National Institute of Respiratory Diseases from Mexico (INER, its Spanish acronym), is a tertiary public care hospital with an installed technological capacity of more than 8,000 medical devices (MDs). Some of these are more than 20 years old, which can increase maintenance costs and/or not have adequate functionality. The Department of Biomedical Engineering of INER, in addition to carrying out the technical and economic evaluation of these DMs, also requires clinical evaluation to make decisions based on evidence for the management of medical technology. Therefore, the objective of this work was to develop a mathematical model for the clinical evaluation of MDs, to know their clinical performance in patient care. Initially, three partial indicators related to the usage, impact and demand of the medical device were defined. Then a mathematical function to determine the Clinical Indicator was defined. The model result was a clinical indicator, and it was applied to a sample of 310 medical devices of ten different type located in nine clinical areas of the INER. This indicator provides an auxiliary criterion for decision-making in the management of the MDs. It can serve as a reference to schedule the relocation of medical devices in clinical areas. As well, it provided information on their performance and/or their effectiveness in the clinical care of the patient.