Introduction: Patient safety in oral and maxillofacial surgery is oriented towards providing patient care by means of adequate risk management that minimises adverse events and fosters a culture of safe clinical practices as the fundamental basis of quality health care. To implement preventive actions are implemented in order to improve patient safety and to reduce the incidence of adverse events, as well as to improve the quality of care. The aim of this report is to implement preventive measures in order to improve the health care of the patient in an Oral and Maxillofacial Surgery Unit by reducing the Adverse Events and proving good quality healthcare., Materials and Methods: A longitudinal, prospective, single centre study was conducted using a methodology of analysis of modes of failure and effects of the management of potentially serious adverse events in the Oral and Maxillofacial surgical unit of the University Hospital of Granada (June-November 2017), as well as the preparation and implementation of a series of corrective measures., Results: A total of 33 adverse events were recorded, with 10 of them considered as critical, distributed in different areas of care, and referred from Primary Health Care and from other hospitals. Seven preventive actions were implemented: information to the patient, training actions, improvements in the protocols and procedures, in the care process and clinical practice, as well as the need to set up an adequate checklist, and other miscellaneous., Discussion: The implementation of preventive measures represent a notable advance in the prevention of harm to the patient and the organisation, involving healthcare staff in a safety culture oriented towards quality care., (Copyright © 2018 FECA. Publicado por Elsevier España, S.L.U. All rights reserved.)