Objective: to investigate the effectiveness of using the complex of β-glucans Immunsil™ D3 in patients with frequent exacerbations of chronic obstructive pulmonary disease (COPD). Object and methods of research. 42 patients with COPD who had 2–4 clinical exacerbations during the previous year were under observation for 2 years. Patients of the 1st group (n=22) received tiotropium bromide and standard treatment for exacerbations; patients of the 2nd group (n=20) additionally used Immunsil™ D3 1 capsule 2 times a day for 1 month. Results. The use of the Immunsil™ D3 complex ensured an increase in the number of cells with the activity of natural killers and cells of the monocyte-macrophage series, and also contributed to the recovery of the immunoregulatory index (p<0.05). These changes were largely leveled off by the end of the 2nd year of observation. The use of the Immunsil™ D3 helped to reduce the number of exacerbations of COPD (p>0.05) and significantly reduced the need for antibiotics in patients with COPD (p<0.05) for 1 year. During the next year of observation, the difference between the groups was significantly less pronounced. Conclusion. Immunsil™ D3 can be recommended for patients with COPD with frequent clinical exacerbations. It is advisable to annually repeat the course of β-glucans in patients with frequent clinical exacerbations of COPD.