High‐resolution diffraction utilizing an analytical electron microscope has been employed to identify small (∼500 A˚‐diam) precipitates attached to line dislocations in gallium arsenide. The results show that the precipitates consist of crystallites of elemental hexagonal arsenic embedded within the gallium arsenide matrix. Precipitates were observed in a range of semi‐insulating, p‐type, and n‐type material and were not dependent on the presence of specific additional dopants for their occurrence. The way in which the particles may originate is discussed.