Purpose: This study was performed to examine the neck failure patterns after a complete response (CR) to definitive radiotherapy for advanced head and neck cancer patients, as well as evaluate the clinical significance of the results of this study. Materials and Methods: Between 1987 and 2008, the clinical data of patients who had been treated with radical radiotherapy for primary squamous cell carcinomas and enlarged cervical lymph nodes was analyzed retrospectively. Ultimately, the cases that showed CR of the cervical lymph node lesions to full-dose radiotherapy were included in this study. The recurrent rate and sites in the cervical lymphatic area were evaluated periodically by radiologic imaging studies, along with some factors which might have affected the rate of recurrence. Results: A total of 73 patients who achieved CR in neck area after radiotherapy were included in this study. The rate of subsequent neck failure among those patients was 19.2%. There was only a 5.5% failure rate in the 55 patients who underwent radiotherapy in their primary site. Eighty percent of the recurrent cases were found within 3 years (median follow-up, 68 months). The majority of neck recurrent cases (47%) were accompanied with the failure of the primary lesions. The initial response of the primary site and the method of radiotherapy simulation were significant prognostic factors associated with the nodal recurrence rate. Conclusion: The recurrence rate of cervical nodes in patients with CR to radiotherapy in the primary site and neck area was about 5%. These patients could be followed up with close observation without a planned neck dissection.