The displacement energy E d in the 110 direction, which is a good approximation to the polycrystalline value in face-centred cubic metals, has been measured in type 316 austenitic steel at high temperatures using a high-voltage electron microscope to both produce and observe loop growth, dislocation flux and void swelling as a function of electron energy. In the loop growth experiments the threshold voltage for displacements was directly measured, in the other methods the normalized results were compared with Oen's calculated cross sections assuming various values of E d. The latter method assumes that the effect per electron is independent of dose rate, and this has been verified for void-swelling. The results obtained from all the experiments lie in the range E d = 18 ± 1.5 eV.