Introduction: The purpose of this paper is to present the level of protease-antiprotease balance disorder with patients hospitalised for acute COPD depending on the stage of the condition in relation to smokers and non-smokers. Materials and Methods: The research was carried out on 61 patients with COPD. They consisted of 27 women and 34 men; 32 smokers and 30 non-smokers, age 18-82 (average 59.9&plusmn;12 years). All patients underwent: measurement of concentrations: alfa-1-antiproteinase (&#945;₁-PI) and elastase (EN) (ELISA Immuno Diagnostic) in serum. Results: A negative Spearman correlation between the concentration of elastase and the concentration of 1-antiprotease in the group of patients with severe and serious COPD and in the smokers&#8217; group; respectively (r=&#8211;0.845 and p=0.001); (r=&#8211;0.529 and p=0.014) and (r=&#8211;0.506 and p=0.003). Statistically significant difference of elastase concentrations between the severe COPD group (by GOLD) and the remaining groups with p<0.05. Statistically significant difference of EN and α₁-PI concentrations between the groups of smokers and non-smokers; with p<0.0001 and p=0.027. Conclusions: Patients with COPD develop a severe protease-antiprotease balance disorder to the advantage of proteases. The balance disorder increases together with an increase in the level of COPD. Smoking increases the protease-antiprotease balance disorder and constitutes a significant risk factor for the intensification of irreversible obstructive changes within the respiratory system with patients with COPD. Giving up smoking causes a decrease in the adverse changes in the balance and is the most significant factor that improves the prognosis for patients with COPD.