Kimura's disease is an uncommon, chronic inflammatory disease of unknown etiology. It is an important category of reactive lymphadenopathy in the oriental population. The most common sites are the subcutis of the head and neck, and parotid gland. It's clinical course is benign nature. The treatment modalities for this disease are steroid therapy, radiation therapy and surgical excision. We experienced a case of soft tissue mass in the left arm. It was slightly tender and relatively movable. We excised the mass, which was turned out to be Kimura's disease on microscopic examination.