The aim of this study was to compare the effects of formoterol, ipratropium bromide and a placebo on walking distance, lung function, symptoms and quality of life (QoL) in chronic obstructive pulmonary disease (COPD) patients. A total of 183 patients (mean age 64 yrs, 86 female) with moderate-to-severe nonreversible COPD participated in this randomised, double-blind, parallel-group study. After a 2-week placebo run-in, patients were randomised to formoterol Turbuhaler 18 microg b.i.d. (delivered dose), ipratropium bromide 80 microg t.i.d. via a pressurised metered dose inhaler, or placebo for 12 weeks. Inhaled short-acting beta2-agonists were allowed as relief medication and inhaled glucocorticosteroids were allowed at a constant dose. The primary variable was walking distance in the shuttle walking test (SWT). Baseline mean SWT distance was 325 m, mean forced expiratory volume in one second (FEV1) was 40% predicted. Clinically significant improvements in SWT (>30 m) were seen in 41, 38 and 30% of formoterol, ipratropium and placebo patients, respectively (not significant). Mean increases from run-in were 19, 17 and 5 m in the formoterol, ipratropium and placebo groups, respectively. Both active treatments significantly improved FEV1, forced vital capacity, peak expiratory flow and daytime dyspnoea score compared with placebo. Formoterol reduced relief medication use compared with placebo. Neither active treatment improved QoL. Formoterol and ipratropium improved airway function and symptoms, without significant improvements in the shuttle walking test.