ABSTRACT INTRODUCTION Antibiotic resistance is an increasing problem throughout the world. In Norway the resistance problem is still at a low rate due to a strict antibiotic policy. There has been shown in several studies that inapproriate antibiotic prescription is associated with emergence of resistant strains of bacterias. The aim of this study is to evaluate how good the quality of precribing practice is at the Asker and Bærum hospital. MATERIALS AND METHODS The study was conducted at Asker and Bærum hospital. A primary and secondary care hospital with 250 beds, situated twenty kilometers west of Oslo, Norway. There were approx. 34000 hospital admissions in 2006. Prevalence data of antibiotic prescription were collected on six independent days during winter and spring 2007. The patients included in the study received both antibactrial and antimycotic therapy (ATC J01 and J02) on six different wards. Patients receiving profylactic treatment were excluded. In 2006 a local antibiotic guideline booklet were distributed at the hospital. This antibiotic guideline booklet were the golden standard for defining quality of prescibing practice. A flow chart made of specialists in microbiology, infectious disease, anesthetics and with help from international expertise, was the tool to asess the quality of every antibiotic prescription. Strict criterias was used for inclusion of quality indicators in the flow chart. Indication of antibiotic treatment, choice of antibiotics and dosage were the three indicators chosen. These three indicators were then catagorised in subgroups: indication and no indication (I1, I2), choice were divided in choice 1to choice 8(C1-C8) and dosage (D1-D5). RESULTS 464 antibiotic prescriptions made the basis of evaluation. In 92,6 % the antibiotic treatment were justfied (e.g I1). The choice of antibiotic were adequate (C1) in 80,8 %, and the dosage were according to guidelines (D1) in 78,4 %. If we summeries these three indicators, as we did with every drug prescription, we find a total adherence to guidelines at the hospital in 63,4 %. DISCUSSION This study shows that in spite of apparently good antibiotic control in norwegian hospitals, inapproriateness in prescribing practice do occur at a wide range at Asker and Bærum hospital. The study also shows great variability in prescription quality inwards at the hospital. There were significant differencies in quality of prescribing practice between the surgical units and the medical ones. Where the medical units were much more adherent to the local guidelines.