Kimura's disease is an uncommon, chronic inflammatory disorder of unknown etiology that is seen in an endemic form in the Orient. It usually presents as a mass in the subcutaneous tissue of the head and neck region or the major salivary glands, and is often associated with a regional lymphadenopathy. The patients have peripheral blood eosinophilia and elevated IgE levels but are otherwise usually healthy. We encountered the case of a 33-year-old man who had a soft tissue mass in his left distal arm which was diagnosed as being Kimura's disease.