The hydrogen sorption properties of ZrFex (1.9 <= x <= 2.5) alloys were studied by measuring Pressure-Composition (PC) absorption and desorption isotherms at pressure up to 300 MPa. The increase in the Fe content in alloys leads to increase in hydrogen absorption and desorption pressures of hydrides and reduction of the beta ->alpha phase transition enthalpy while both the atomic hydrogen content in hydrides (H/M) and the hydrogen capacity expressed in wt % H-2 decrease. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.