We have studied the use of Oxygen (O2) in our hospital, evaluating the prescription criteria and also the control and degree of therapeutic compliance. The study was completed with an opinion survey to physicians and nurses on different aspects of oxygen-therapy at the hospital. 50 inpatients under treatment with O2 have been studied. Clinical records and therapeutic prescriptions were reviewed. 47 patients had a previous gasometry, of them 44 had Respiratory Insufficiency (RI). 26 patients were controlled during oxygen-therapy: 15 were still on RI and two had their treatment modified. The compliance of treatment was evaluated through a visit in a non regular hour, 18 patients (36%) were not following oxygen therapy. When a new gasometry was performed it was observed that 21 patients (42%) continued in RI. The survey showed that a high number of physicians and nurses consider that oxygen therapy is done inadequately, being this fact attributed to several factors. There are errors in the handling of O2 at the hospital, possible related with the routine associated to an established therapy and also because O2 is a continuous therapy which requires a permanent level of attention both from the health care personnel and from the patient.