Background: Thyroid lobectomy is the preferred option for small, unifocal papillary thyroid carcinoma. Involvement of the central neck lymph nodes is an indication for total thyroidectomy plus central neck dissection. We aimed to verify if frozen section examination of ipsilateral central neck nodes can identify the subgroup of patients scheduled for thyroid lobectomy intraoperatively who could benefit of more extensive initial operative treatment. Methods: Ninety-four consenting patients with clinically unifocal cN0 papillary thyroid carcinoma underwent thyroid lobectomy plus ipsilateral central neck dissection with frozen section examination. If the frozen section examination was positive for metastases, a completion thyroidectomy and a bilateral central neck dissection were accomplished during the same procedure. Results: Frozen section examination identified occult nodal metastases in 25 of the 94 patients who then underwent immediate completion thyroidectomy and bilateral central neck dissection. Overall, central neck node metastases were found at final histology in 35 cases: occult micrometastases were observed in additional 9 patients and nodal metastases ≥2 mm in additional 1 patient. Conclusion: Intraoperative assessment of nodal status obtained with ipsilateral central neck dissection and frozen section examination is able to change the extent of thyroidectomy in about one-fourth of patients scheduled for thyroid lobectomy. Frozen section examination appears a safe and effective strategy to decrease the need of a second-step completion procedure and, theoretically, the risk of recurrence.