A small‐angle neutron scattering (SANS) study of the structure of II‐VI semiconductor crystallites in a semiconductor‐doped glass is presented. The scattered intensityI(k) exhibits a peak at a nonzero scattering vector and decreases to zero askgoes to zero. The data are interpreted with a simple phenomenological model, based on local mass conservation, which describes a dilute gas of crystallites surrounded by depletion zones. We show that SANS allows a quick and accurate measurement of the average size and of the volume fraction of the crystallites, and we give values of both quantities for a commercial series of glasses.