Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis (Lyell Syndrome) are severe, multisystem disease caused mainly by reaction to drugs. The clinical features include: changes on the skin and mucosa as well as lesions in the internal organs. There are no standards of treatment in this diesease group. There are ongoing trials in various groups of drugs. Apart from providing the appriopriate conditions and symptomatic treatment, immunoglobulins, cytostatics and plasmapheresis are used. The authors present the clinical course of a patient with Stevens-Johnsons Syndrome, probably caused by klaritromycin. The 13 y.o. boy was admitted to a Department of Paediatric Surgery specializing in treatment of burns. Immunoglobulin, cytostatics, antibacterial and antiviral drugs were used as well as topical medicines routinely applied in burns. The method proved to give good results. The treatment of Stevens-Johnsons Syndrome is difficult and expensive. Due to lack of standards, the treatment depends on one's own experience and up to date literature.