BACKGROUND: This randomized, double-blind, multicenter study was designed to evaluate the efficacy of inhaled once-daily fluticasone furoate (FF) administered in the evening in patients with persistent asthma not controlled by short-acting beta(2) agonists, and to determine the dose(s) suitable for further development. METHODS: Of 1459 patients screened, 598 received one of six treatments: placebo, FF (25 μg, 50 μg, 100 μg or 200 μg) once daily each evening, or fluticasone propionate (FP) 100 μg twice daily for 8 weeks. The primary endpoint was change from baseline in pre-dose evening forced expiratory volume in 1 s (FEV(1)). RESULTS: A dose-response effect was observed for once-daily FF 25-200 μg including (p <0.001) and excluding placebo (p = 0.03). FF 50-200 μg once daily significantly increased FEV(1) from baseline (p <0.05 vs placebo), by >200 mL for FF 100 μg and 200 μg. Significant improvements were also achieved for peak expiratory flow, and percentage symptom-free and rescue-free 24 h periods. The magnitude of effect was at least as good as twice-daily FP. Overall, once-daily FF was well tolerated with no systemic corticosteroid effects. CONCLUSION: FF 50-200 μg/day once daily in the evening demonstrated dose-related efficacy in asthma with 100-200 μg appearing to be the optimal doses for further evaluation. ClinicalTrials.gov: NCT00603382.