A model is described which identifies the oxide growth stresses observed in many systems with the diffusion of anions along oxide grain boundaries and the subsequent formation of an oxide intrusions at the oxide/metal interface. Detailed calculations are made of the elastic stress system within the metal and of the average stress developed in the oxide. For a Pilling-Bedworth ratio greater than unity, the oxide intrusion acts as a linear center of dilatation generating short-range tensile stresses within the metal and equivalent compressive stresses within the oxide. It is shown that the average value of the oxide stress increases with both the oxide grain size and with the lateral dimensions of the oxide intrusion.