A patient 62 year-old women was suffered from Lyell's syndrome after taking traditional medicine. Objective: 1/ To describe the clinical cours. 2/ To make comment on results of subclinical: (blood biochemistry, urine analysis, blood count). 3/ Drugs used. Subject: The patient with Lyell's syndrome, was triggered by traditional medicine, admitted and treated at the department Emergency Quynh Lap National Leprosy Dermatology Hospital from February 13th to March 30. Method: to describe the clinical course, subclinical (Blood biochemistry, urine analysis, blood count). Results: Fever, skin pain, skin necrosis, blisters and/or epidermal detachment, mucous membrane erosions and crusting. Blood biochemistry and blood count, urine analysis are normal. After treatment, the patient was cured and discharged.