Inflammation of nasal mucosa plays an essential role in the development of sinusitis. Topical nasal steroids are helpful to reduce the mucosal swelling. In this study, the efficacy of topical nasal steroid spray combined with antibiotic for the treatment of sinusitis was studied in a double blind trial. Two randomly assigned groups were treated with amoxicillin / clavulanate potassium combined with topical nasal steroid spray of either budesonide or placebo to each nostril twice a day for 3 to 4 weeks. Clinical symptoms and signs decreased significantly in both treatment groups, but the difference between study groups was not statistically significant.