Background. Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been validated, the utility of intraoperative ultrasound (US) in modified radical neck dissection (MRND) has not been reported in the literature. The aim of this study was to analyze the utility of intraoperative SPUS in assessing the completeness of MRND for thyroid cancer. Methods. Between 2007 and 2011, a total of 25 patients underwent MRND by 1 surgeon for thyroid cancer. All patients underwent intraoperative SPUS, which was repeated at the end of the neck dissection (completion US) to look for missed lymph nodes (LNs). Results. There were 10 male and 15 female patients. Pathology included 23 papillary and 2 medullary carcinomas. The number of LNs removed per case was 23 +/- 2, and the number of positive was LNs 5 +/- 1. In 4 (16%) cases, intraoperative US detected 7 residual LNs, which would have been missed, if completion US were not done. These missed LNs were located in low-level IV (3 nodes), high-level II (2 nodes), and posterior level V (2 nodes) and measured 1.4 +/- 0.2 cm. At follow-up, recurrence was seen in 2 (8%) patients, including a superior mediastinal recurrence in a patient with tall cell cancer and a jugular LN recurrence at level II in another patient with papillary thyroid cancer. Conclusion. This pilot study shows that intraoperative SPUS can help assess the completeness of MRND. According to our results, intraoperative completion US identifies LNs missed by palpation 16% of the time.