The kinetics of short and long-range ordering in FeAlx alloys have been investigated using resistometry. The results were obtained in the A2 solid solution (x = 0.10 and 0.17), in the DO3 ordered phase (x = 0.23, 0.27, 0.30 and 0.33) and in the A2 + DO3 two-phase region (x = 0.19). The ordering kinetics curves are well described in a classical model with a lognormal distribution of relaxation times whose center varies with the temperature according to an Arrhenius law. One thus gets the thermodynamic quantities which drive the atomic mobility. The data display a strong decrease of the activation energy with Al content and with the formation of the D03 structure, as well as very short relaxation times. Such an abnormally high atomic mobility can be attributed to a decrease of the migration energy through a lattice dynamics effect, similar to that recently proposed by several authors to explain the enhanced diffusion in some bcc transition metals and alloys.