The magnetic susceptibility of ReF6 has been measured in the range 4°—296°K using the Faraday method. The susceptibility in the range 14°—296°K can be expressed by means of MχReF6=(78±1)×10-4/T+(0.87±0.03)×10-4, from which one calculates a moment of 0.25 Bohr magnetons. Applying a theory developed for gaseous ReF6 [W. Moffitt, G. L. Goodman, M. Fred, and B. Weinstock, Mol. Phys. 2, 109 (1959)] to the magnetic measurements reported here gives ζ=3160 cm—1 and 10Dq/α=55 000 cm—1, where α is an orbital reduction parameter connecting the dl2g and deg levels. The diamagnetic susceptibility of WF6 has been remeasured and preliminary measurements on TcF6 are reported.