Background: Once-daily dosing with an effective inhaled corticosteroid (ICS) would likely enhance compliance and, therefore, aid in the management of asthma. Objective: Several once-daily dosing regimens of mometasone furoate (MF) administered by dry powder inhaler (DPI) were compared with a twice-daily dosing regimen in 286 patients with mild to moderate persistent asthma who were previously being treated with ICS. Methods: During a 2-week open-label phase, patients received MF-DPI, 200 mug twice daily. They were then randomized to continue MF-DPI, 200 mug twice-daily treatment or to receive MF-DPI, 200 mug once daily in the morning (AM), 200 mug once daily in the evening (PM), 400 mug once daily AM, or placebo as part of the 12-week, double-blind phase. The primary efficacy variable was the mean change from the baseline to endpoint (last evaluable observation) for FEV1. Results: Once-daily MF-DPI, 400 mug, AM maintained FEV1, and morning peak expiratory flow rate, FVC, FEF25%-75%, and asthma symptom scores, at levels similar to those fur MF-DPI, 200 mug twice daily and significantly better than placebo. Once-daily MF-DPI, 200 mug, PM was effective in maintaining pulmonary function, but was less effective on other efficacy measures. In comparison to the other MF-DPI groups, once-daily MF-DPI, 200 mug, AM was not as effective overall. The incidence of local adverse events, including oral candidiasis, was low with all dosages. Conclusions: Once-daily MF-DPI, 400 mug, AM was as effective as MF-DPI, 200 mug twice daily, whereas once-daily MF-DPI, 200 mug, was more effective when administered in the evening compared with morning, for patients receiving ICS therapy. Once-daily dosing offers an effective and convenient treatment that could aid compliance in the treatment of asthma.