The hydrogen-storage properties of the zeolites Na-LEV, H-OFF, Na-MAZ and Li-ABW have been investigated at 77 K and pressures in the range 0 - 1.6 MPa. The maximum hydrogen-storage capacity was up to 2.07 wt% on zeolite Na-LEV, 1.75 wt% on zeolite H-OFF, 1.64 wt% on zeolite Na-MAZ and 1.02 wt% on zeolite Li-ABW at 1.6 MPa, respectively. The experimental data showed that a large volume of micropores and a suitable diameter near to the kinetic diameter of a hydrogen molecule are important for improving the hydrogen-storage capacity of zeolites. (c) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.