The post operative hypoxemia may delay the recovery from surgical damage, exacerbate organ dysfunction and contribute the mortality. The old patients are increased in the medical situation nowadays, the incidence of perioperative complications are also increased including post anesthetic hypoxemia. Herein we analysed the post operative hypoxemia in transference of the operated patient to the recovery room using pulse oximeter. During the period of 9 months from Mar. 1988, 32 patients with over 60 years old and ASA class 2 or 3 were included in this study. Hypoxemia was defined as less than 90% SaO2, (arterial oxygen partial pressure (PaO2 = 58 mmHg)). SaO2of the patient who breathed the room air for 5 min. after extubation (group 3) and just arrived at PAR (group 4) was significantly lower than preoperative SaO2(p<0.05). Hypoxemia occured in 18.8% of the patients in group 3 and 25% in group 4. During the short term period as transfering the operated patients to the recovery room the incidence of hypoxemia increased by 6.2%. There was no significance in change of pulse rate or systolic blood pressure statistically. Because surprising high incidence of hypoxemia in geriatric patients, the monitoring of the SaO2 and oxygen supply are mandatory in the high risk patients during postoperative transfer to the PAR.