BACKGROUND: According to the literature, 25% to 50% of antimicrobials prescribed in hospitals are unnecessary or inappropriate, directly impacting antimicrobial resistance. Thus, the present study aimed to evaluate the use of antimicrobials in a university hospital in Northeast Brazil, using days of therapy (DOT) and length of therapy (LOT) indicators in accordance with the latest national and international recommendations for monitoring the use of antimicrobials. METHODS: This is an observational, prospective analytical study conducted in a teaching hospital, with 94 active beds, distributed between the intensive care unit (ICU), the surgical clinic (SUR), the medical clinic (MED), the pneumology/infectology department (PNE/INF) and pediatrics (PED). The duration of the study was from the beginning of January to the end of December 2018. RESULTS: During the study period, a total of 11,634 patient-days were followed up and 50.4% of the patients were found to have received some antimicrobial, with a significant reduction in use of 1% per month throughout the year. Patients were receiving antimicrobial therapy for 376 days in every 1000 days of hospitalization (LOT = 376/1000pd). Overall, the 1st-generation cephalosporins and fluoroquinolones were the most used in respect of the number of prescriptions and the duration of therapy. The calculated global DOT/LOT ratio showed that each patient received an average of 1.5 antimicrobials during the hospital stay. The incidence of antimicrobial resistance, globally, for both methicillin-resistant Staphylococcus aureus (methicillin R), Carbapenem-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii (Carbapenem R), was 1 per 1000 patient-days. CONCLUSIONS: The results obtained from the analyses revealed that half of the patients admitted to the hospital who took part in the study were exposed to the use of antimicrobials at some point during their stay. Although moderate, it is noteworthy that there was a decline in the use of antimicrobials throughout the year. The indicators used in this study were found to be very effective for gathering data on the use of antimicrobials, and assessing the results of the initiatives taken as part of the Stewardship program.