The aim of this study was to evaluate the role of neck ultrasonography compared to (131)I whole-body scan (WBS) and circulating thyroglobulin (Tg) measurement after thyroid hormone withdrawal in the follow-up of children with thyroid papillary cancer, who had previously undergone total thyroidectomy for the diagnosis of neck lymph node metastases (LNM). Forty-five children were examined. Neck ultrasonography and diagnostic WBS were conclusive about the presence or absence of LNM in 35 patients. Diagnostic WBS revealed the presence of LNM in 6 cases not detected by neck ultrasonography; neck ultrasonography was positive in 3 cases that were negative at diagnostic WBS but confirmed by post-(131)I therapy WBS. One patient with suspicious neck lymphnodes at neck ultrasonography not confirmed by WBS was considered as a false-positive result of neck ultrasonography. Neck ultrasonography and thyroglobulin (Tg) were conclusive about the presence or absence of LNM in 29 patients. Tg was elevated in 10 subjects with negative neck ultrasonography (7 had also lung and/or mediastinic LNM). Tg was undetectable in 5 patients in whom the presence of LNM was confirmed by neck ultrasonography and WBS. In conclusion, our study in children demonstrates that neck ultrasonography can detect LNM that are not suspected by palpation, diagnostic WBS, or serum Tg determination. Furthermore, neck ultrasonography can pinpoint the anatomic site of the LNM.