The use of x-ray photoelectron diffraction (XPD) for the structural study of oxide growth on Ni(001) from c(2×2)O up to the saturated oxide of approximately two-monolayers thickness is described. Some rather unique structural information is obtained from XPD. This includes the site type and position of the c(2×2) overlayer and the geometry and lattice parameters of the saturated oxide. The XPD data are also in excellent agreement with single-scattering cluster calculations at the spherical wave level.