Subarachnoid hemorrhage is a neurovascular emergency affecting relatively young adults. A ruptured cerebral aneurysm is the main non-traumatic cause. Except for the non-specific symptom of headache, which frequently occurs in subarachnoid hemorrhage, the clinical presentation is atypical, making the diagnosis difficult with possible dramatic consequences. The diagnosis is based on the CT scan without contrast, which, when negative, will be followed by a lumbar puncture. The etiologic analysis is based on an urgent arteriography, revealing the characteristics of the aneurysm such as the anatomy of the intracerebral vessels, the identification of the bleeding site and the size and location of the aneurysm. The main complications are bleeding relapse, hydrocephaly and vasospasm. Early treatment is based on the final repair of the aneurysm through two possible approaches: microvascular neurosurgical clipping or coiling via endovascular access. This article discusses the diagnostic and therapeutic aspects of subarachnoid hemorrhage.