Introduction: Drugs are regarded as valuable therapeutic and preventive instruments; however, there are no risk-free drugs. All of them have side effects, and some have serious consequences such as increased antimicrobial resistance. In this work, the different indications for which antimicrobials were prescribed by dentists were analyzed, in order to take intervention measures that help to achieve their rational use.   Methods: All the antimicrobial prescriptions received during twelve months by the drugstore of a social service institute were analyzed; the prescriptions contained data on medications, dosage, quantity and diagnosis. The critical analysis of the prescriptions was made according to quantitative and qualitative aspects.   Results: The most prescribed antibiotic was azithromycin, followed by amoxicillin/clavulanic acid; however, the scientific literature recommends penicillins as the first choice in the pharmacological treatment of oral pathologies, with azithromycin being reserved for allergy to amoxicillin. Drugs prescribed from the qualitative point of view are of high therapeutic value, when there are groups of drugs that are not of choice for dental pathologies, macrolides (clarithromycin and azithromycin), third generation cephalosporins (ceftriaxone, etc.) and quinolones (ciprofloxacin and levofloxacin).   Conclusion: We must become aware of the importance of the rational use of antibiotics in the dental clinical practice when looking for a successful treatment that minimizes side effects and drug resistance.