The torsion- and Knudsen-effusion techniques were used to determine the temperature dependence of the vapour pressure of solid indium(III) iodide, Ig(p/kPa)= (12.30 +/- 0.30) - (6520 + 100).(K/T), valid in the temperature range from 399 K to 479 K. By second- and third-law treatment of the vapour pressure data, the standard sublimation enthalpy, Delta(sub)H(m)(o)(T = 298.15 K) = (136 +/- 5) kJ . mol-(1), was derived. 1997 Academic Press Limited.