Chronic rhinosinusitis (CRS) is a recalcitrant inflammatory process which has a marked detrimental impact on quality of life. At the present there is no cure for this condition, measures are taken to stop progression, and provide symptomatic relief. Topical corticosteroids are commonly prescribed in the management of CRS, but few trials show effectiveness in clinical settings. We set up a randomized, double-blind, placebo-controlled trial to study the effectiveness of a topical corticosteroid agent--fluticasone propionate aqueous nasal spray (FPANS) in patients with CRS. We measured symptoms, diary card, and rigid endoscopy scores, acoustic rhinometry, middle meatal swabs, blood tests--CRP, ESR, WBC, and eosinophil count. Measurements were done at the start of the trial, at 8 weeks, and 16 weeks where possible. Twenty-two patients completed the trial, 9 received FPANS, and 13 had placebo. There was no difference between the 2 groups on all counts. When patients were considered as one group, there was an improvement in the diary card scores (p = 0.054), comparing baseline to 8 or 16 weeks. There was no evidence that the regular use of topical corticosteroid increased the risk of developing an infection. An important observation was that the topical corticosteroid did not precipitate acute sinusitis. There is compelling evidence that topical corticosteroids down-regulate cytokine expression, and it is likely that a larger, and longer multi-centre trial may prove their efficacy in CRS.