Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and not completely reversible obstruction of the airways associated with an abnormal inflammatory response of the lungs to particles and noxious gases related to a systemic effect. Inflammatory processes are suggested to be involved in pathogenesis of COPD. The aim of the study was to investigate the relation among to the mortality rate, hospitalization period and inflammatory mediators of the patients with COPD attack on admission into the emergency department. A total of 87 subjects with COPD attack were contributed in this study. TNF-α, IL-6 and catalase were determined in addition to leucocyte count (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). There was no significant difference between the deceased and discharged patients in terms of WBC, ESR, CRP, IL-6, and TNF-α. However, mean catalase levels of discharged patients were significantly higher than the deceased patients (p<0.05). Significant correlations were observed between WBC and hospitalization period, and CRP and follow up period in the intensive care unit. We can suggest that catalase activities on admission into the emergency service were decreased in deceased patients who were in follow up in intensive care unit with COPD attack. High CRP and WBC levels were also related with the hospitalization period of patients with COPD attack.