By the use of x‐ray and neutron topography, spin‐density‐wave (SDW) domains in pure chromium (IOCHROME), both in the virgin state and after field cooling, have been found to be of the order of a few mm in length and of several mm3in volume. The change in configuration of the domains before and after field cooling is reasonable. This was found in a nearly perfect well‐characterized sample. In a strain‐annealed sample, the domain size was below the resolution.