We report a patient who sought treatment for an acute subarachnoid hemorrhage as a result of an intracranial aneurysm. Management included early surgical repair and intraoperative monitoring of evoked potentials. Pan-angiography revealed berry aneurysms of the communicating anterior artery and right middle cerebral artery. Surgery was uneventful, and the somatosensory evoked potential monitoring did not show any abnormalities. Nevertheless, the patient showed a neurological deficit due to a clip-related infarct in the right middle cerebral artery territory characterized by a right hemiparesis with no sensory deficit. This case report supports the possibility of false-negative results in single-mode intraoperative monitoring during aneurysm surgery.