COPD (Chronic Obstructive Pulmonary Disease) is a respiratory disease characterized by progressive and largely irreversible airway limitation and extrapulmonary problems. The prevalence of COPD increases with age. Mental health problems, including cognitive capacity limitations, occur frequently. Patients with COPD may have problems with cognitive functioning, either globally or in single cognitive domains, such as information processing, attention and concentration, memory, executive functioning and self-regulation. Possible causes are hypoxemia, hypercapnia, exacerbations and decreased physical activity. Cognitive problems in these patients may be related to structural brain abnormalities, such as gray matter pathologic changes and the loss of white matter integrity. Because of the negative impact on health and daily life, it is important to assess cognitive functioning in patients with COPD in order to optimize patient-oriented treatment and to reduce personal discomfort, hospital admissions and mortality.