 Several reports published recently have questioned many of the routine uses of oxygen and some evidence even seems to point towards negative outcomes in some of these conditions. Specifically, excessive oxygen is likely to do more harm than good in the neonatal period, following cardio-pulmonary resuscitation and likely following acute myocardial infarction. Prospective, randomised studies on this important use of oxygen in the preoperative string are, however, lacking in the literature and in view of theoretical risks for hyperoxemia to several organs, the routine use of high oxygen fractions during the peri-operative phase can be questioned. 