ObjectivesRadioiodine therapy could be challenging in chronic renal failure patients requiring hemodialysis. The aim of this study was to establish the effects of hemodialysis on elimination of radioiodine from the body in thyroid carcinoma patients with end-stage chronic renal failure and to determine its effects on environmental radiation dose.Materials and methodsThree end-stage chronic renal failure patients (four cases) diagnosed with differentiated thyroid carcinoma requiring radioiodine therapy were included in our study. Each patient was given 50-75 mCi (1850-2775 MBq) iodine-131 with 50% dose reduction. Dose rate measurement was performed at the 2nd, 24th, and 48th hour (immediately before and after hemodialysis) after radioiodine administration. The Geiger-Muller probe was held at 1m distance at the level of the midpoint of the thorax for the dose rate measurement.Results and conclusionThe effective half-life of iodine-131 for three patients was found to be 44h. In conclusion, the amount of radioiodine excreted per hemodialysis session was calculated to be 51.25%.