Chronic obstructive pulmonary disease (COPD) is a multifactorial disease, in which systemic inflammation plays a key role. This 6-month randomized double-blinded placebo-controlled study evaluates the possible effect of natural preparation Inflaminat on clinical symptoms of COPD, indicators of respiratory function, and exacerbation frequency in 60 patients with moderate severity of COPD. Inflaminat is a combination of natural ingredients black elder (Sambucus nigra L.) berries, violet (Viola tricolor L.) herb, and calendula (Calendula officinalis L.) flowers. The preparation has been previously demonstrated to possess anticytokine and anti-inflammatory effects in experimental studies. In present study, COPD dynamics were evaluated by means of BCSS (Breathlessness, Cough, and Sputum Scale) and spirometry tests. It was shown that 6-months Inflaminat administration led to significant decrease of BCSS points from 3.0 ± 0.6 to 1.9 ± 0.7, (p = 0.002) as well as significant increase of FEV1 from 66 ± 18% to 73 ± 17%, (p = 0.042); there were no beneficial dynamics in placebo group. Side effects associated with preparation administration were not identified. The results of the study suggest that Inflaminat may be employed in treatment of patients with moderate severity of COPD, since it has a positive effect on COPD symptoms according BCSS and indicators of respiratory function FEV1.