This study compared the efficacy and safety of once-daily umeclidinium 62.5 µg with once-daily glycopyrronium 50 µg in patients with moderate-to-severe chronic obstructive pulmonary disease. This was a 12-week, multicentre, randomised, open-label, parallel-group study (Clinicaltrials.gov: NCT02236611). Patients were randomised 1:1 to umeclidinium 62.5 µg or glycopyrronium 50 µg administered via Ellipta or Breezhaler dry powder inhaler, respectively. The primary endpoint was trough forced expiratory volume in 1 s (FEV1) at day 85 in the per-protocol population. Other endpoints included: weighted mean FEV1 over 0-24 h and patient-reported outcomes (transition dyspnoea index score and St George's Respiratory Questionnaire total score). Adverse events were also assessed. A total of 1037 patients were randomised to treatment. Umeclidinium was non-inferior (margin: -50 mL) to glycopyrronium (trough FEV1 at day 85 treatment difference: 24 mL, 95% confidence intervals: -5-54). Improvements in other endpoints were similar between treatments. Adverse event incidences were similar for umeclidinium (37%) and glycopyrronium (36%). Once-daily umeclidinium was non-inferior to once-daily glycopyrronium in patients with chronic obstructive pulmonary disease in trough FEV1 at day 85. Patient-reported outcomes and safety profiles were similar for both treatments.