Uremia affects thyroid functions and hypothyroidism occurs in end-stage renal disease (ESRD) patients. However, thyrotoxicosis occurs in ESRD patients rarely. Most of the published reports about thyrotoxicosis in ESRD patients are related with thyroid cancer and maintenance on hemodialysis. Therefore we wanted to share our experience about therapy and outcomes of three thyrotoxic peritoneal dialysis (PD) patients without thyroid cancer. Clinical manifestations were nonspecific because uremia masked thyrotoxic symptoms. Hyperthyroidism was due to BasedowGraves disease in two patients and toxic nodular goiter in one patient. All patients were treated with both anti-thyroid drugs (propylthiouracil and propranolol) and radioactive-iodine (RAI) therapy. No side-effects were seen due to anti-thyroid drugs but hypothyroidism developed after radioactive iodine therapy in all patients. Clinical manifestations of thyrotoxicosis may be masked in ESRD patients. Therefore thyrotoxicosis need to be thoroughly investigated. Anti-thyroid drugs may be used safely in PD patients. But if RAI therapy is used, patients must be evaluated for hypothyroidism after RAI therapy. We speculate that a uremic toxin with poor peritoneal clearance may affect thyroid functions and cause thyrotoxicosis in PD patients.