AbstractPurposeIn this study, the extent and pattern of inpatient and outpatient antimicrobial drug use was investigated in Rijeka, Croatia, and the impact of control measures was evaluated.MethodsConsumption of antibacterials for the years 2000 and 2001 was monitored using the ATC/DDD methodology.ResultsDuring the investigation period, the antimicrobial utilization at the University Hospital Center (UHC) Rijeka has decreased by 14%. In the outpatient setting of the County of Primorje and Gorski kotar, the antimicrobial utilization was similar during both years. At the UHC Rijeka, not only the amount, but the pattern of antibacterial utilization also has changed in contrast to the outpatient setting where the pattern of antimicrobial prescribing remained the same.ConclusionsThe control measures for antibiotic use that were introduced in the outpatient setting did not influence the prescribing habit of primary care physicians, while the impact of hospital antibiotic use control measures was satisfactory. Further investigation is needed to evaluate the impact of these measures on bacterial resistance patterns. Copyright © 2003 John Wiley & Sons, Ltd.