The chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide. Recently, international guidelines for diagnosis, prevention and therapy have been published. Now also a modified German version of these guidelines is available. The diagnosis and the severity of the disease is established on the basis of spirometric findings. All stages of COPD are treated with bronchodilators (beta 2-sympathomimetics and anticholinergics). In addition, in stage II and III theophylline and inhaled corticosteroids may be used. Systemic steroids should be restricted to acute exacerbations. For patients with advanced COPD long-term oxygen therapy and in selected cases surgical procedures may be indicated. Rehabilitation measures are of high value. Strategies for primary prevention and smoking cessation programs are extremely important. To get to the diagnosis of COPD as early as possible, all smokers with cough and phlegm should undergo spirometry.