Abstract The intermetallic semiconducting compound In 2Te 3 is based on a defect zinc-blende (or fluorite) structure, and it is possible to cause ordering of the lattice vacancies. Experimental work has been carried out to investigate the methods by which specimens in this ordered state may be produced, and the ordering temperature briefly investigated. The ordered structure has been investigated by X-ray powder methods, and analyses carried out to determine the details of atomic arrangement in the ordered structure. It is shown that although the ordering lines can be indexed on a three-fold cubic cell, as suggested by Inuzuka and Sugaike, no structure based on a cell of this size can predict correctly the observed reflections. This problem has been studied independently in two laboratories, starting from different premises and predicting different structures. One analysis, assuming that only the normal zinc-blende atomic sites are available for ordering, predicts a body-centred orthorhombic structure with space group Imm2. The second view, assuming that enantiomorphous fluorite sites are possible positions of indium atoms in the ordered material, predicts a higher symmetry tetragonal structure with space group either P 42mcm or P 42nm. The two analyses are presented separately, and it is then concluded that the experimental evidence available from powder work is not sufficient to enable a choice to be made between the two structures.