Hydrogen storage in metallic thin films in the form of metal hydride have a great potential to solve the hydrogen storage challenges and also thin films offer an opportunity to grow new samples fast with novel structures. In the present work the ex situ study on structural, optical and hydrogen storage properties of Pd-capped Mg thin films have been investigated. The nano structured Pd-capped Mg thin films have been prepared by DC magnetron sputtering on glass substrate. The as deposited and hydrogenated samples have been characterized by XRD and FESEM. The content of hydrogen in thin films has measured by using Elastic Recoil Detection Analysis (ERDA) technique with 120 MeV107 Ag+9 ions. The temperature dependent hydrogen contents in thin film samples have been estimated and the saturation of hydrogen absorption has been observed at 250 degrees C among all studied samples. In the optical reflectance spectra, Mg hydride samples have been observed partially transparent in comparison to as deposited Mg film. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.