Clinical applications for the use of oxygen have extended beyond the hospital setting to home therapy. In patients with hypoxemic chronic obstructive pulmonary disease, long-term administration of oxygen has been substantiated as beneficial in terms of improved survival, decreased hospitalization, increased exercise capability and endurance, enhanced neuropsychologic function, and alleviation of hemodynamic abnormalities. Continuous oxygen therapy with use of an ambulatory system consistently provides the greatest benefit. New developments that have facilitated home oxygen therapy are conservation methods that allow flow of oxygen only during inspiration or storage of oxygen during expiration and cosmetic improvements for concealing devices used to administer oxygen. Controlled studies are needed to determine the optimal duration and method of administration of oxygen and the selection of appropriate candidates for long-term home oxygen therapy.