There are no specific therapeutic guidelines for thyroid cancers confined to the isthmus. To determine whether isthmic papillary thyroid carcinoma (PTC) can be treated with thyroid isthmusectomy and limited neck dissection, we analyzed factors related to central lymph node (CLN) metastasis in patients with clinically node-negative (cN0), solitary, isthmic PTC. We retrospectively reviewed 73 consecutive patients who underwent surgery for solitary isthmic, PTC. The frequency, pattern, and risk factors of CLN metastasis were analyzed. Occult CLN metastasis and paratracheal lymph node (PTLN) metastasis were detected in 34 patients (46.6%) and 28 patients (38.4%), respectively. On multivariate logistic regression analysis, male sex and tumor size >0.7 cm were associated with CLN metastasis, and age ≤38 years, tumor size >0.6 cm, and pretracheal lymph node positivity were associated with PTLN metastasis. Thyroid isthmusectomy for solitary isthmic PTC may be insufficient in patients with tumors >0.6 cm, those aged ≤38 years, and male patients. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1510-E1514, 2016.