Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death. Although the underlying pathomechanism remains poorly understood, COPD is accompanied by increased cellular stress and inflammation. We investigated serum contents of heat shock proteins (HSP 27, 60, 70, 90 alpha), 20S proteasomes, C-reactive protein (CRP), and interleukin-6 (IL-6) in patients with mild or severe COPD, healthy smokers and nonsmokers. HSP27, HSP70 and HSP90 alpha were significantly altered in patients suffering from COPD as compared to controls. HSP27 and HSP70 are potential novel serum markers for the diagnosis of COPD in the smoking population. This is the first study to demonstrate elevated serum levels of the described heat shock proteins in patients with COPD. We showed sensitivity and specificity of serum HSP27 and HSP70 as diagnostic markers for COPD.