Background and Objectives : To assess the usefulness of computed tomography image before papillary thyroid cancer surgery, focus on confirmation of lateral cervical lymph node metastasis not detected by ultrasonography. Material and Methods : From January 2008 to May 2009, total 150 patients who had undergone thyroid surgery and been confirmed papillary thyroid cancer pathologically were enrolled. They had taken neck computed tomography following the ultrasonography. Results : Computed tomography had found suspicious metastatic lateral neck lesion in 13 patients. After the image study, lateral neck lymph node dissection had been included in their surgical plan. Of these, only 7 cases were confirmed pathologically lateral neck lymph node metastasis(positive predictive value=0.54). Taken as whole 150 patients, additionally 4.7% of patients confirmed lateral neck lymph node metastasis by preoperative computed tomography. Conclusion : If preoperative ultrasonography was performed precisely, additional benefits that could be achieved by computed tomography were not much.