Acute episode of chronic obstructive pulmonary disease occurs in almost all patients, during which cough, expectoration and dyspnea increase. When the underlying disease is not severe and the acute episode not life-threatening, the term "exacerbation" is appropriate, and the patients can be managed at home. When the underlying disease is advanced and the acute episode possibly life-threatening, the terms of "acute respiratory failure" or "decompensation" can be used. These patients are most often admitted to the hospital, and at times to the intensive care unit. Bronchodilators and respiratory physiotherapy form the basis of the management of acute episodes of COPD. In severe cases, oxygen must be administered, and the decision of an hospitalisation considered. Antibiotics and corticosteroids shoud not be prescribed in a systematic manner. In the most severe cases, non-invasive ventilation must be accessible. The prevention of acute episodes of COPD is best achieved through tobacco cessation and influenza vaccine. Finally, an acute episode may be an opportunity to make a diagnosis of COPD if this has not been done before.