Oxygen therapy for the end-stage COPD patient should include a portable component. Accordingly, any system should be small and lightweight in order to enable the chronically debilitated patient to be as active and mobile as possible. Standard continuous flow oxygen via nasal cannulae is reliable and effective but it is also very wasteful. As a result, oxygen conserving methodologies have emerged to improve the efficiency of oxygen delivery and have served to lighten the load for these patients. These devices include: reservoir cannulas, transtracheal catheters and demand pulsing delivery devices. They provide oxygen savings from 2:1 to 7:1 over continuous flow delivery. In addition to rendering the newer oxygen systems more portable, they can also reduce the cost of oxygen and its associated service. As patient requirements are highly individual, the wide choice of available methodologies permits the clinician to prescribe the system that best suits the needs of the patient.