The hydrogen storage has been studied in several series of porous Prussian blue analogues but not in the iron one, T-3[Fe(CN)(6)](2) with T = Mn, Co, Ni, Cu, Zn, Cd. In this contribution the study of the H-2 adsorption in that series of porous solids is discussed. For comparison, the H-2 adsorption isotherm in Fe-4[Fe(CN)(6)](3) was also recorded. All the samples to be studied were characterized from energy-dispersed spectroscopy, X-ray diffraction, infrared, Mossbauer, and thermogravimetric data. The cavity volume to be occupied by the hydrogen molecule was estimated from the amount of water molecules found within the cavity. The obtained value for the cavity volume was then used to calculate the density for the hydrogen storage within the cavity. The obtained density values remain below the value corresponding to its liquid state (71 g/L). (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.