Raman spectroscopy was used for determining the stresses generated in the chromia scales formed on pure chromium by thermal oxidation in dry oxygen or in pure water vapour. After oxidation, the residual stresses in the oxide scale are compressive, and depend on several parameters, among which the oxidation conditions (nature and partial pressure of the oxidant) and oxide thickness. A stress gradient through the oxide scale was underlined by measurements on a taper section of the metal/oxide system. Compressive stresses seemed to be stronger at the oxide surface compared to the metal/oxide interface. In the case of oxide scales generated in water vapour, a duplex morphology was observed, and ft was noticed that the stresses are lower in the equiaxed and fine grained inner layer than in the compact and coarse grained outer layer. These features let imagine partial relaxation of stresses by creep within the inner part of the scale grown in water vapour. In dry oxygen the poor adherence of the oxide induced rapid relaxation by buckling and spalling.