Recent studies demonstrated clinical significance of the presence of traumatic subarachnoid hemorrhage (tSAH) on the initial CT-scan after head injury. Investigations show similarities between traumatic and aneurysmal SAH suggesting that a similar therapeutic approach as used in spontaneous SAH patients might be beneficial in tSAH patients. Evidence of the clinical significance of the finding of tSAH on CT after head injury and the beneficial use of the calcium antagonist nimodipine in tSAH patients are reported.