Formation of novel hydrides from ZrNi5 alloy has been confirmed experimentally. After exposure of ZrNi5 at 0.9 GPa(H-2) and 100 degrees C for 6 days the alloy transformed into two hydrogenated phases alpha and beta containing initially more than 0.38 and 0.86 hydrogen atoms per formula unit respectively. At ambient conditions both hydrides were extremely unstable. Major part of hydrogen desorbed within few minutes. During this desorption the lattice parameters of both hydrides were continuously reduced what confirms their solid solution character. (C) 2011 Elsevier B. V. All rights reserved.