We performed radiotherapy in a 28-year-old patient with Kimura's disease of the orbit. Irradiation with 21.6 Gy was administered to the tumor bed with a single dose of 1.8 Gy in 5 weekly fractions delivered via a high-energy linear accelerator (6-MV X-ray). Complete remission of the tumor and improvements in the neurological findings were achieved. Neither tumor regrowth nor late complications were detected up to 84 months after radiotherapy. Radiotherapy is an effective treatment for Kimura's disease of the orbit.