Abnormal thyroid hormone production and metabolism are relatively common in chronic renal failure and in regular haemodialysis. Chronic kidney disease is associated with decreased thyroid hormone concentrations, especially triiodothyronine (T3), which are referred to as the euthyroid sick syndrome associated with increased severity of non-thyroidal illness and mortality in cats and dogs. Hyperthyroidism is a very unusual condition in patients undergoing regular haemodialysis. Graves' disease is rare in these patients. To our knowledge, till now only 8 well documented cases of Graves' disease have been reported in patients undergoing regular haemodialysis. The diagonsis of Graves' disease must be evoked in presence or even in the absence of specific symptoms of the disease in haemodialysis patients. Diagnosis of hyperthyroidism may be difficult because of similar signs and symptoms as in uremia and manifestions are inhabitual. Indeed, hypertension, gynaecomastia, anaemia and hypercalemia can be seen in the two pathologies. Amost all patients undergoing regular haemodialysis received iodine 131 therapy for the treatment of Graves' disease. This treatment is efficient and safe. Isolation of the patient is not recommanded. The risk for dialysis staff is to be contaminated by an accidental ingestion of a biologic fluid from the patient. The usual protection barriers used during the haemodialysis session are sufficient.