There is extensive evidence of the efficacy of anti-microbial drugs in preventing infections from surgical efforts. Our objective was to describe the results obtained in our annual surgical antibiotic prophylaxis (SAP) audit in the years 2013-2017.This was a retrospective observational study of SAP in surgical procedures carried out between 2013 and 2017 in a tertiary-level hospital. We examined the results from the services of general surgery, vascular surgery, neurosurgery, the breast unit, otolaryngology, maxillofacial surgery, traumatology, urology, pediatric surgery, gynecology, and plastic surgery.Establishment of six process quality indicators and their evaluation in the annual audit were carried out by the pharmacy service for approximately 500 operations. The indicators that had a high percentage of compliance were indication for SAP, choice of anti-microbial agent, dose and route of administration, and administration of an intra-operative dose when this was appropriate. In contrast, time of administration of the first dose and duration of prophylaxis had a worse percentage of compliance.Compliance with the SAP protocols in our hospital is high. We consider that these better results are attributable to the establishment of quality indicators of SAP and to the annual audit that evaluates said indicators. Communication of the results obtained in the audit to the surgical services, which have as part of their objectives included in their management contracts compliance with said SAP protocols, encourages improvement. The use of prophylaxis kits is an improvement strategy that facilitates the correct choice of anti-microbial agent and prevents SAP from being prolonged inappropriately.