Chronic obstructive pulmonary disease (COPD) exacerbations are evaluated from a history of the disease, its clinical symptoms, and laboratory tests. The most common causes of a COPD exacerbation are upper respiratory tract and tracheobronchial infections. The exacerbation severity usually corresponds to the magnitude of clinical manifestations of COPD during its stable course. Successful treatment in patients with a COPD exacerbation is determined by its timely diagnosis. When treating patients with a mild or moderate exacerbation of Stages I-II COPD in an outpatient setting, it is advisable to use ascoril having broncholytic, mucolytic, and mucokinetic properties along with antibiotics and glucocorticosteroids, if clinically indicated.