The article presents the results of the authors' trial involving 119 patients (aged 22 to 82 years) with severe bronchial asthma (BA) diagnosed according to the ERS/ATS guidelines (2014). Allergic asthma was diagnosed in 77% of patients. The study focused on house dust mites as the main allergens in the sensitization spectrum. A significant proportion of patients (82%) had uncontrolled course of the disease, and 76% suffered from airflow limitation that is not fully reversible. Markers of eosinophilic airway inflammation (nitric oxide in exhaled air and level of blood eosinophils above 150 cells per 1 µL) were found in 63% of patients. Good adherence to treatment (administration of more than 75% of the prescribed doses of drugs) was observed in 61% of patients. Among patients with severe asthma 27% were active smokers. Smokers demonstrated a decreased pulmonary function and a lower level of nitric oxide in exhaled air. Smokers were also less adherent to treatment with inhaled corticosteroids. Severe BA was combined with COPD in 37% of cases