We presented a case of acute febrile neutrophilic dermatosis (Sweet's syndrome) in 57 years-old female. This case is the 31 st case in the literature and the first case in Korea. Erythematous plaque was presented on the face with tendency of recurrences. Histologically a dense inflammatory cell infiltration composed predominantly of polymorphonuclear neutrophiles, lmphocytes and histiocytes was seen in dermis. Positive laboratory findings were polymorphonuclear leukocytosis and elevated ESR. The symptoms were well centrolled with orally administered preclnisolone.