In this study, we report the first clinically identified case of severe fever with thrombocytopenia syndrome (SFTS) in a 73-year old man from Jeju Island, South Korea. Although his initial manifestation suggested tsutsugamushi disease with cutaneous lesion, later the patient presented with symptoms characteristic of SFTS. Despite intensive medical therapies upon the clinical diagnosis of SFTS, patient``s condition rapidly deteriorated. SFTS is a fatal disease that requires early diagnosis and appropriate supportive treatment.