The present report describes an acute subdural hematoma (ASDH) associated with subarachnoid hemorrhage (SAH), due to ruptured cortical aneurysm. To our knowledge, extremely rare cases of this sort have been reported so far. A 23-year-old male patient without previous trauma presented with severe headache and rapidly decreasing level of consciousness to decerebrate status. Computed tomography (CT) scan has demonstrated an ASDH together with SAH. Hematoma has immediately been evacuated without any evaluation by angiography. After evacuation of the thick subdural clot, a 10-mm aneurysm was revealed on a precentral artery of frontal cortex, which was ligated. However, after 35 days the patient discharged with left side hemiparesis and dysphasia, and just after several months of admission he got symptom free. Ruptured cortical aneurysm should be considered as one of the causes of spontaneous ASDH. Vascular anomaly investigations are suggested for these cases, thus CT angiography or digital subtraction angiography has to be considered if clinical condition allows.