Cerebral vasospasm is a well-known phenomenon that has been associated with subarachnoid hemorrhage due to aneurysmal bleeding. It can lead to serious outcomes if not recognized and treated promptly. It happens most frequently following cases of aneurysmal subarachnoid hemorrhage. Other causes include traumatic brain injury, reversible cerebral vasoconstriction syndrome, post-tumor resection, and non-aneurysmal subarachnoid hemorrhage. We describe a case of severe clinical vasospasm following acute on top of chronic spontaneous subdural hematoma in a patient with corpus callosum agenesis. Also, a small literature review of the possible risk factors of such occurrence is discussed.