Backgroud: Subarachnoid hemorrhage (SAH) is sudden bleeding into the subarachnoid space. The most common cause of spontaneous SAH is a ruptured aneurysm. Symptoms include sudden, severe headache, usually with loss or impairment of consciousness. It has a lot of dangerous complications especially re-bleeding and vasospasm which are the major causes of death and disability. Objective: To study on clinical characteristics, computed tomography brain imaging, causes and complications of subarachnoid hemorrhage. Subject and method: A cross-sectional prospective study on 202 patients who suffered from subarachnoid hemorrhage admitted to the Stroke Center, 108 Military Central Hospital from June 2018 to January 2020. Result and conclusion: The average age was 60.5 years. The most common age group was among the aged 45-64 years (71.2%). The most common symptoms of SAH was sudden severe headache (98%); neck stiff (86.1%), followed by consciousness disorders (56.9%), systolic blood pressure above 160mmHg (50.5%), focal neurologic deficits (20.3%). The Fisher classification: Grade 1 (4.5%), grade 2 (17.3%), grade 3 (19.3%), grade 4 (58.9%). The ruptured cerebral aneurysm accounted for 89.6% of the causes of SAH. The most common site of aneurysm was in the anterior communicating artery (34.8%), followed by the middle cerebral artery (21.5%) and in the internal carotid artery (16.6%). Posterior cerebral circulation accounted for 12.7%; 4.4% of patients had multiple aneurysms. The most common complications of SAH was cerebral vasospasm (26.2%) and typically occurred between 5 and 7 days after SAH, followed by rebleeding accounted for 7.9%, the most cases occurred within the first 24 hours, acute and subacute hydrocephalus (10.4%), hyponatremia (11.4%) and seizures (5.4%).