We present the case of a 34-year-old man undergoing craniotomy for arteriovenous malformation resection under general anesthesia who suffered a tonic–clonic seizure captured by intraoperative electroencephalograph. The seizure was extinguished with a propofol bolus. This patient had no previous history of seizures, and no precipitating cause was identified. Intraoperative electroencephalographic seizures under general anesthesia have been recorded previously in the literature, but our observation is the first to demonstrate this with overt motor manifestations. We also discuss the differential diagnosis of an intraoperative seizure under general anesthesia and provide guidance to the anesthesiologist who encounters this event.