For the first time it has been established that hydrogen action stimulates evolution of the recrystallization and recovery of mechanical properties of deformed palladium; so under the hydrogen action recrystallization develops at lower temperatures than it takes place at classical recrystallization annealing. A physical nature of the phenomenon is discussed on the basis of a theory of hydrogen treatment of materials. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.