Based on the density functional theory, we investigate and discuss how hydrogen behaves at the edges of graphite sheets/layers, in particular the zigzag edge. Our calculation results show that the zigzag edge is very reactive. It is possible to dissociatively adsorb H₂ on these surfaces without any activation barrier hindering the reaction. To be able to use carbon nanomaterials as a means to store hydrogen, one of the crucial factors necessary would be the ability to dissociate hydrogen first, and then (somehow) induce them to stick to the carbons on each sheets. The results we present here suggest the possible utility of the zigzag edge as a reaction channel to carry out the aforementioned process. [DOI: 10.1380/ejssnt.2004.77]