Chronic effects of oxitropium bromide were studied in patients with pulmonary emphysema. Pulmonary function tests, an exercise test, and a questionnaire were used. Seven subjects underwent two successive studies, including a questionnaire on QOL, pulmonary function tests, and an exercise test before and after one month or more of regular inhalation of ocitropium bromide (600 micrograms/day). The complaint of breathlessness was significantly reduced and the ability to perform activities of daily living had improved slightly after the treatment. There were no significant differences in the values of arterial oxygen pressure at rest. The VC, RV/TLC, and peak expiratory flow rate improved. A significant decrease in oxygen uptake at rest, a slight decrease in minute ventilation at rest, and a significant prolongation of exercise time were observed after the treatment. No other changes were noted. We conclude that oxitropium bromide may improve lung mechanics and reduce the work of respiratory muscles.