Many patients with chronic obstructive pulmonary disease (COPD) episodically or continuously have asthmatic signs with a degree of reversibility in response to bronchodilators. In such cases, the diagnosis 'chronic asthmatic bronchitis' is often used, although the cause-effect relationship between COPD and asthmatic manifestations is not established. Hence, the 'chronic asthmatic bronchitis' is not a pathogenetic diagnosis, but rather a working diagnosis which implies a specific treatment of the reversible component of chronic airway obstruction. Certainly, the most important measure to avoid a rapid progression of COPD is the elimination of damaging agents by inhalation (smoking). In addition, it was a widely accepted belief that these patients require a continuous inhalation therapy with beta-agonists or anticholinergics. However, there is new evidence, indicating that a continuous treatment might accelerate the decline in ventilatory function and that a better long-term outcome might be achieved by on-demand inhalations.