The oxidation of a high silicon content nitrogen containing austenitic stainless steel has been studied at 1173degreesK for 100 hours under synthetic air. The results are compared with those of a traditional 18Cr-8Ni stainless steel and show that the increased silicon content has a marked and beneficial effect. The oxidation behaviour of the high silicon content steel was shown by thermogravimetric data to have a weight gain 7.53 times less than the classical steel after 100 hours. Scale adhesion characteristics are improved and associated with the formation of a continuous SiO2 sub-scale beneath the main Cr2O3 scale. This continuous silica layer conferred increased protection against high temperature oxidation.