A patient presented with hyperthyroidism and end-stage renal disease requiring hemodialysis that was difficult to control despite increased dosages of anti-thyroid drugs. The condition could finally be controlled by 131I radioactive iodine therapy (RIT) and hemodialysis provided under a hospital-linkage system. During three hemodialysis sessions after the oral administration of 131I, we measured the radioactivity released from the patient and the radioactivity of the devices/tools used. The radioactivity of the devices/tools was managed by allowing the isotope to decay into non-radioactive elements. Our experience suggests that outpatient RIT may provide a safe and convenient means of treating Graves' disease, even in patients receiving hemodialysis.