The goal of antibiotic prophylaxis in Odontology is to prevent the onset of infections through the entranceway provided by the therapeutic action, therefore it is indicated providing there is a considerable risk of infection, either because of the characteristics of the operation itself or the patient?s local or general condition. Nonetheless, clinical trials with antibiotics in dental pathologies have had scant regard for the required methodological criteria and, in addition, are not sufficiently numerous. This text presents the results of an expert conference comprising the Presidents of the most representative Scientific Societies in Spain who have analyzed the existing literature and have drawn on their valuable professional experience. It describes the technical circumstances, analyzes the biological and pharmacological foundations and their application to the most representative medical situations. It is concluded that antibiotic prophylaxis in Odontology has certain well-founded, precise indications and offers the international scientific community a practical protocol for action.