Long-term oxygen therapy (LTOT) improves survival of patients with chronic obstructive pulmonary disease (COPD) having severe respiratory failure and chronic hypoxemia. In our study 51 patients received LTOT at home via concentrators (34 males, the mean age, 65.5 ± 7.8 yrs; 17 females, the mean age, 62.8 ± 4.1 yrs). Of them, 37 (72.5 %) survived 6-year period and 14 died (13 males and 1 female). Causes of death were acute respiratory viral infection (in 1 patient), insult (in 1 patient), chronic heart and lung failure (in 12 patients). Survival of patients with chronic restrictive pulmonary diseases was not longer than 3 years. A control group included 45 COPD patients with severe respiratory failure not receiving LTOT (30 males, the mean age, 66.3 ± 8.5 yrs; 15 females, the mean age, 69.1 ± 4.6 yrs). Of them, 16 survived 6 years and 29 died (5 females, the mean age, 72.6 ± 3.6 yrs, 24 males, the mean age, 67.8 ± 5.2 yrs). So, LTOT at home improves survival of COPD patients with severe respiratory failure.