목적: The ATA guidelines for management of PTC patients are well known. According to the changes in the new ATA guidelines in 2009, the recent opinion has led to the development of less aggressive surgical decisions, and now it is in ongoing trials. The purpose of this study was to evaluate the trend of indications of completion thyroidectomy for papillary thyroid cancer over the past decade. 방법:A Total of 266 patients who underwent hemithyroidectomy for PTC from 2003 to 2014 were included. Clinicophalogical parameters such as age, gender, tumor multiplicity, extrathyroidal extension, central node metastasis and clinical outcomes were retrospectively reviewed. 결과:Mean age was 45 years and female was 206 patients (77%). Demographics, preoperative stage were not significantly different between the completion thyroidectomy and hemithyroidectomy groups. The incidence ratio of risk factors(tumor multiplicity, extrathyroidal extension and central lymph node metastasis)after hemithyroidectomy were 40%(2003), 16.7%(2004), 25%(2005), 37.5%(2006), 56.3%(2007), 9%(2008), 39.1%(2009), 63.6%(2010), 47.6%(2011), 28.6%(2012), 52.2%(2013) and 43.7%(2014). The ratio of completion thyrodiectomy to hemithyroidectomy were increased 42.9% to 69.6% from 2004 to 2009, and then were decreased 63.6% to 4.3% from 2010 to 2014. 결론:Recently, a trend has been changed toward clinical observation rather than completion thyroidectomy in patients after hemithyroidectomy with having pathological risk factors.