A given work is concerned with the study of conditions of nanosize omega-phase appearance in Ti- and Zr-based alloys, in which metastable beta-phase is formed after treatment for the sake of a solid solution and quenching. As shown, the omega-phase of such a dispersion may appear in these alloys both under quenching directly and as a result of cold plastic deformation, but it always requires strongly specified concentration of valence electrons. As a result of such an omega-phase appearance, specific structural-phase state manifesting a special mechanical behaviour is formed. First of all, this state is characterized by high-level reversible deformation, which is one of the major requirements to the implant materials.