The effects of blast on biological tissue are documented for some organ systems such as the lung. In the central nervous system (CNS) the mechanism of CNS injury following blast wave is unclear. For example is there a selective effect of blast on varying brain region or white matter bundles. The effect of blast on traumatic brain injury (TBI) has come into particular focus with the Global War on Terror and Operation Iraqi Freedom and Operation Enduring Freedom where TBI has become known as the signature injury of these conflicts. The reason for the prominence of TBI in these particular conflicts as opposed to others is unclear but may result from the increased survivability of blast due to improvements in body armor. In the current series of articles in the Journal some developments of current research concepts in relation to military traumatic brain injury (TBI) are highlighted together with many remaining unsolved questions.