Platelet graphite nanofibers (PGNFs) were synthesized by thermal decomposition from a mixture containing polymer and catalyst. The hydrogen storage capacity of the material was measured using the volumetric method carried out at 298 K at a pressure up to 4.83 MPa. The results show that the PGNF possess a 3.3 wt.% hydrogen storage capacity. The gaseous molecules were adsorbed between two graphene planes in the PGNFs and residual amounts of hydrogen were possession within PGNFs while pressure decreased to ambient conditions. X-ray diffraction was used to understand the PGNF structural modifications before and after hydrogen uptake. We found that the PGNF interlayer undergoes expansion and returns back to the initial value before and after hydrogen uptake. (D 2007 Elsevier B.V. All rights reserved.