Absence seizure is most common in children. It commonly occurs between 5 and 18 years of age; it is not common before the age of 2 years or after adolescence and it is relatively rare in adults over the age of 50. We report a case of electroencephalography confirmed absence seizure and absence status successfully treated with sodium valproate in an elderly patient with dementia. Differential diagnosis between absence status and complex partial seizure is emphasized.