Toxic epidermal necrolysis (TEN) is an epidermolytic skin disorder associated with drug administration. It is associated with an erythematous rash with full thickness epidermal loss and characteristic histology. A 35-year-old woman underwent allogeneic hematopoietic stem cell transplantation (HSCT) for severe aplastic anemia (SAA). She developed an acute epidermolytic rash and TEN was diagnosed on the basis of skin biopsy. In the HSCT setting, TEN should be thought of as an important differential diagnosis of epidermolytic dermopathies. The most distinctive diagnostic test in the differential diagnosis of these disorders is skin biopsy