The purpose of the presentation of this case is evaluating the relation between subarachnoidal hemorrhage and cocaine use. In our case, 29 year - old male was admitted to our clinic due to vomiting and loss of consciousness. We were told that he had a cocaine use history. Subarachnoidal hemorrhage was determined by computerized tomography (CT). Digital substraction angiography (DSA) study showed two aneurysms one of which was at the left internal carotid artery (ICA) and the left middle cerebral artery (MCA) bifurcation. The patient was operated in our clinic by a subfrontal keyhole approach and both of the aneurysms were clipped. During the follow up extraventricular drainage operation was made because of hydrocephalus and after that V-P shunt was applied. He died at 09/10/2003 because of massive G İS hemorrhage which was probably due to DİC. Cocaine may affect clinical presentation and prognosis in the patients with subarachnaidal hemorrhage. It is a common opinion that cocaine use is related with cerebrovascular spazm, infarction, intracranial hemorrhage and hypertension. Additionally, it is shown that aneursym rupture occurs at younger ages in cocaine users.