Objective: Some patients with allergic rhinitis (AR) may prefer nonaqueous intranasal corticosteroid aerosols because of unwanted attributes of aqueous formulations. The mandatory removal of chlorofluorocarbon-propelled nonaqueous aerosols from the market limited available treatment options. To fulfill this unmet need, a nonaqueous, hydrofluoroalkane-propelled beclomethasone dipropionate (BDP) nasal aerosol was developed and approved for treatment of AR nasal symptoms. As part of the development program, this dose-ranging study evaluated three doses of BDP nasal aerosol to determine the optimally safe and effective dose for adolescent and adult patients (>= 12 years old) with seasonal AR (SAR). Methods: After a 7 to 21 day placebo run-in period, eligible patients with SAR were randomly assigned to once-daily BDP nasal aerosol 80 mu g, 160 mu g, 320 mu g, or placebo. The primary endpoint was the change from baseline in average A. M. and P. M. patient-reported reflective total nasal symptom scores (rTNSS) over 2 weeks. Safety and tolerability were also assessed. A potential study limitation could be lack of objective assessment of AR symptoms. Results: Significant improvements were seen in average A.M. and P.M. rTNSS (least squares [LS] mean treatment difference, -0.63; 95% CI: -1.13, -0.13; p=0.013) as well as in average A. M. and P. M. instantaneous TNSS (iTNSS; LS mean treatment difference, -0.60; 95% CI: -1.09, -0.11; p=0.016) with BDP nasal aerosol 320 mg/day compared with placebo. Although there were numerical improvements from baseline in patient-reported rTNSS and iTNSS with BDP nasal aerosol 80 mu g and 160 mu g, these doses did not achieve statistical significance compared with placebo. BDP nonaqueous nasal aerosol was well tolerated at all doses tested, with a safety profile comparable to that of placebo. Conclusions: These data indicate that 320 mu g/day of BDP nasal aerosol is the optimally safe and effective dose for the treatment of SAR in adolescent and adult patients.