The tetrahedral molecule features C-I distances of  2.12 ± 0.02 Å. The molecule is slightly crowded with short contacts between iodine atoms of 3.459 ± 0.03 Å, and possibly for this reason, it is thermally and photochemically unstable.
Carbon tetraiodide crystallizes in tetragonal crystal structure (a 6.409, c 9.558 (.10 nm)).
It has zero dipole moment due to its symmetrically substituted tetrahedral geometry.