Objective: To compare the appropriateness of antibiotic prescribing for upper respiratory tract infections (URTIs) in two countries with different prevalence of antimicrobial resistance: Denmark and Iceland.Design: A cross-sectional study. Settings and subjects. General practitioners (GPs) in Denmark (n = 78) and Iceland (n = 21) registered all patients with URTI according to the Audit Project Odense (APO) method during a three-week period in the winter months of 2008 and 2009.Main outcome measures: Appropriateness of antibiotic prescribing in patients with URTI in Denmark and Iceland.Results: A total of 1428 patients were registered (Denmark: n = 1208; Iceland: n = 220). A majority of patients in both countries were prescribed antibiotics, and only a minority of the prescriptions could be classified as appropriate prescribing. In general, Icelandic GPs more often prescribed antibiotics (Iceland = 75.8% vs. Denmark = 59.3%), but Danish GPs had a higher percentage of inappropriate antibiotic prescribing for sinusitis, and Icelandic GPs for pharyngotonsillitis. No differences were found for acute otitis media (AOM). The different antibiotic prescribing patterns between Denmark and Iceland could not fully be explained by different symptoms and signs among patients.Conclusion: Icelandic GPs have a higher antibiotic prescribing rate compared with Danish GPs, but the percentage of inappropriate antibiotic prescribing is highest in Denmark for sinusitis, and in Iceland for pharyngotonsillitis.Key pointsWithin the Nordic countries there are marked differences in antimicrobial resistance and antibiotic use.Iceland differs from Denmark by a higher antibiotic prescribing rate and a higher prevalence of antimicrobial resistance.The majority of antibiotics are prescribed in primary care and most often for upper respiratory infections (URTIs).Only a minor amount of antibiotic prescriptions for URTIs can be classified as appropriate; inappropriate antibiotic prescribing is higher in Denmark than in Iceland for sinusitis and the opposite for pharyngotonsillitis.The different antibiotic prescribing patterns between Denmark and Iceland cannot be fully explained by different clinical criteria among patients.