Toxic epidermal necrolysis (TEN) is a severe mucocutaneous adverse reaction characterized by extensive necrosis and detachment of the epidermis more than 30 percent of the body surface area (BSA). It is most commonly triggered by medications such as anti-epileptics, sulfonamide antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). A 22-year-old woman who did not have any underlying medical history presented with painful multiple various sized erythematous bullae and plaques on whole body for 1 day. On the second day of hospitalization, the bullae progressively coalesced and detachments of the 60 % of body surface area of epidermis were occurred. On the 5th day of hospitalization, she had a tonic clonic seizure with eyeball deviation for 5 minutes. We transferred her to an intensive care unit (ICU) and administered lorazepam 4 mg and levetiracetam 1500mg. We checked brain computed topography, magnetic resonance imaging and cerebrospinal fluid study, but there were no abnormalities. Although she had delirium and additional seizures during the treatment in the ICU, she was improved without any complication after 3weeks of inpatient treatment. There are many complications of TEN such as dehydration, malnutrition, sepsis, ophthalmic and pulmonary complications, but the seizures are rare. Herein, we report a case of seizure to the patient who has no family and personal history during TEN treatments.