ABSTRACT
Tachycardia (115 beats/minute) was detected in the physical examination before tonsillectomy operation of a 6 - year - old, male patient. ECG (sinus rhythm) and blood pressure were normal except for tachycardia. Causes of tachycardia were sought and could not be found. Only iodised salt ingestion over the past one year was reported in the history. Thyroid hormones were within the normal limits. Cease of tachycardia was seen 26 days after the ingestion of iodised salt was stopped, no other medication was given. The case was followed in the outpatient clinic for one year. Thyroid hormones and heart rate were normal through the year.