Forty-five patients in Southampton who received domiciliary oxygen were visited at home to find out how they used and coped with their oxygen. Generally, the organisation and administration of supplies presented no problems, nearly all the apparatus complied with the drug tariff, and most patients coped well with the equipment. Only two patients were taking oxygen for prescribed periods; the others were taking it when necessary for symptomatic relief. No patient received oxygen for over five hours daily. Most patients thought that they were helped by oxygen, but only four said that it allowed them to increase their level of activity, and the overall benefit seemed slight. This was partly because oxygen was usually limited to one room, so patients used oxygen after rather than during exercise. The amount of oxygen consumed differed widely, ranging from three and a half cylinders a week in three patients to less than one cylinder in six months in 17 patients. The average yearly cost of oxygen per patient ranged from 500 pounds in patients consuming one cylinder or more per week, to 15 pounds in those consuming less than one cylinder in six months. The main cost of domiciliary oxygen is determined by the number of cylinder refills, so patients who use it infrequently are a relatively small drain on resources.