Background and Objectives : Although it is well established that patients with papillary thyroid microcarcinoma (PTMC) have a highly favorable prognosis, the extent of thyroid surgery for PTMC remains unclear. According to the 2011 revised Korean Thyroid Association guideline, the choice of surgical strategy(total thyroidectomy versus lobectomy) for PTMC depends on solely preoperative diagnostic scrutinies-ultrasonography and fine needle aspiration cytology. We want to know how accurately these preoperative diagnostic scrutinies define the choice of surgical strategy for PTMC. Materials and Methods : For 119 patients who underwent total thyroidectomy with central neck dissection for PTMC, retrospectively, we compared the choice of surgery according to preoperative work up and postoperative pathologic findings. Results : Overall accuracy of the choice of surgery by preoperative work up was 61%. Among patients recommended lobectomy on preoperative work up, completion thyroidectomy on postoperative pathology might be necessary for 60% of patients and hidden central node metastasis was revealed in 31% of patients. Conclusions : The results of this study compel us to reinvestigate the current treatment guideline for PTMC. On current guideline according to the sonography and fine needle aspiration cytology, it might be thought to be better to choose more aggressive surgical strategy.