The aim of this study was to assess the use of antibiotics in hospitals and different departments over 14 years (2006-2019) and the impact of various national activities related to this, including national audits of the use of antibiotics for systemic use. The consumption of antibiotics for systemic use (J01) from all Slovenian hospitals (n = 29) and five departments (internal medicine, surgery, ICU (medicine, surgery), paediatrics and gynaecology/obstetrics) was collected. Total hospital consumption was expressed as the number of defined daily doses (DDDs) per 1000 inhabitants per day (DID), the number of DDDs/100 bed days and the number of DDDs/100 admissions. Over 14 years, J01 hospital consumption increased by 13.8%, expressed in DDDs/100 bed days (p = 0.002). In 2019, compared to 2006, the consumption of J01, expressed in DDD/100 bed days, increased from 19.9% to 33.1% in all departments, except intensive care units. J01 consumption expressed in DDD/100 admissions increased by 7.0% to 39.4% in all but paediatric wards (where it decreased by 12.7%). In all years, we observed large variations in the consumption of antibiotics in departments of the same type. The effectiveness of audit interventions aimed at optimizing antibiotic consumption exhibited notable variation across hospitals, with specialized facilities generally demonstrating superior outcomes compared to general hospitals.