The adsorption of atomic H on the bimetallic FeNi(111) surface has been studied by ASED-MO tight binding calculations. The energy of the system was calculated by the atom superposition and electron delocalization molecular orbital (ASED-MO) method. Seven H locations on the alloy surface were selected and the hydrogen atom was positioned in their energy minima configurations. By ASED-MO calculations, the H atom presents its most stable position when it bonds on top Fe atom at 1.5 angstrom and, on bridge Fe-Fe at 0.7 angstrom, respectively. In these cases, the strength of the local Fe-Fe bond decreases 12% and 33% of its original bulk value, respectively. As a consequence of Fe-H interaction, a decohesion mechanism in the Fe-Fe bond could be evidenced. On the other hand, the Fe-Ni and Ni-Ni superficial bonds are slightly modified between 0.4 and 2%. A discussion based on electronic structure studies using the concept of density of states (DOS) and crystal orbital overlap population (COOP) curves is presented. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.