A male patient with atrial fibrillation aged 74 years underwent an operation for benign hypertropic prostate under spinal anesthesia. Post-operatively he suffered from convulsions but was discharged without sequlae on the 1Sth post-operative day. The causes of symptcnmatic fits include hypoxia in general, cerebral edema, embolus hyperpyrexia, drugs, hypoglycemia, hypocalcemia and concomitant diseases including cerebrovascular accidents. Probably a combination of some of these factors caused have caused post-operative or post-spinal anesthesia convulsions.