The primary objective of this study is to determine the optimum dose of BEA 2180 BR inhalation solut ion delivered by the Respimat ? inhaler once daily for four weeks in patients with COPD.

1. Patients must have relatively stable, moderate to severe airway obstruction with an FEV1 >=30% and <= 60% of predicted normal and FEV1 <=70% of FVC at the baseline PFTs at Visit 1 (at both timepoints).
2. All patients must have an increase in FEV1 of at least 12% from baseline (th e -10 minute measurement) 45 min after inhalation of 80 ?g Atrovent MDI.
3. Male or female patients 40 years of age or older.
4. Smoker or ex-smoker with a history of more than 10 pack years.

1. Patients with any other significant disease will be excluded. 2. Patients with a history of asthma or allergic rhinitis will be excluded.