Hemodialysis, forced potassium diuresis, chelating agents per os, and Dithiocarb given intravenously during short periods of time were used for the treatment of acute thallium poisoning (ingestion of 750 mg of thallium sulfate), and the effectiveness of these different therapeutic procedures was analyzed. Chelating agents per os (Prussian blue, Dithiocarb, and Dithiozone) were ineffective in our patient, since fecal excretion of thallium was very low and unmodified by them. Forced potassium diuresis and hemodialysis were very useful therapeutic measures, especially in the first 12 days following ingestion. Dithiocarb perfusion seems to be the most effective method for enhancing urinary thallium excretion. This method might be most useful in the treatment of thallium poisoning if its deleterious effects could be eliminated.