Beclomethasone dipropionate (BDP) nasal aerosol has an established efficacy and safety profile for short-term allergic rhinitis (AR) treatment. However, managing perennial AR (PAR) symptoms often requires long-term treatment. This study evaluates efficacy and safety of long-term treatment with BDP nasal aerosol in PAR patients. In this double-blind, placebo-controlled study, patients (≥12 years [n = 529]) were randomized 4:1 to once-daily treatment with BDP nasal aerosol at 320 μg or placebo. The primary efficacy end point was change from baseline in weekly averages of patient-reported 24-hour reflective total nasal symptom score (rTNSS) over 30 weeks. Safety and tolerability of BDP nasal aerosol were also assessed. Ocular safety, including changes in intraocular pressure and severity of lens opacities (nuclear opalescence, nuclear color, cortical lens opacity, and posterior subcapsular lens opacity), was measured for patients who completed 52 weeks of treatment (n = 245). Across 30 and 52 weeks, BDP nasal aerosol significantly improved rTNSS and instantaneous TNSS (iTNSS) versus placebo (least-squares mean treatment difference, rTNSS, -0.97 for 30 weeks and -1.09 for 52 weeks, p < 0.001 for both; iTNSS, -0.96 for 30 weeks and -1.10 for 52 weeks], p < 0.001 for both). BDP nasal aerosol was well tolerated. Incidence of most adverse events with BDP nasal aerosol was similar to that with placebo, except for epistaxis, which occurred more frequently with active treatment. Severity of changes from baseline in ocular lens opacities was comparable between treatments. BDP nasal aerosol at 320 μg once daily was safe and effective for long-term PAR treatment, with no evidence of clinically adverse systemic safety events. This study was a part of the clinical trial NCT00988247 registered at www.ClinicalTrials.gov.