Background: Despite improved preoperative diagnostics, incidental postoperative detection of differentiated thyroid cancer in the final histology is still common. In most of these cases, completion thyroidectomy is recommended by national and international guidelines, although secondary surgery is associated with an increased operative risk. The optimal timing of completion thyroidectomy is still controversial. Patients and Methods: The patients admitted to surgical oncology department, SECI, with diagnosis of differentiated thyroid cancer; during the period from January 2008 to December 2015; were rewired for age, sex, type of 1 st operation, histopathological result, type of 2 nd operation and time interval between the 2 operation, complication of 2