Severe plastic deformation by torsion was applied to refine the structure of Ni3Al intermetallic compound. Transmission electron microscopy (TEM) observations revealed that in as-deformed state the intermetallic crystal structure was disordered. In order to investigate the dynamics of the transition from the disordered to the L1(2) lattice structure, in situ TEM annealing experiments were performed. These experiments and studies of the bulk material have revealed details of the processes taking place during annealing of severely deformed Ni3Al. (C) 2003 Elsevier Science B.V All rights reserved.