Background and Objective: Unreasonable prescription and indiscriminate use of antibiotics bring about increased antimicrobial resistance. Evaluating the pattern of use seems to be a perfect procedure to improve its reasonable prescription. The objective of this study was to evaluate pattern of antibiotic use in different units of  Zanjan Vali-Asr Teaching Hospital.

Materials and Methods: This was a retrospective and descriptive surveillance study carried out in Vali-Asr Hospital, a teaching hospital under the supervision of Zanjan University of Medical Sciences, by using ATC/DDD international system which has been advised by the World Health Organization (WHO) over a period of one year (2011).

Results: Total number of antibiotic use in the selected hospital was 79/79 DDD/100 bed days during the study. Infectious Unit of the hospital has been used most frequently (27%) than other units. The most frequent antibiotics used in the hospital units were Cephalosporins followed by Macrolides and Fluoroquinolones with a mean of 48.5%, 17.22% and 12%, respectively.

Conclusion: In comparison with similar studies, on average the prescribing rate of antibacterials in Vali Asr Hospital might have been less than other hospitals in Iran. This study puts forward a series of useful methods for subsequent planning interventions and policies to improve quality of antibiotic prescription.