PURPOSE: The aim of this retrospective analysis was to analyze the results of radiotherapy administered to patients with neck node metastases from an unknown primary cancer, with or without neck dissection. MATERIALS AND METHODS: From January 1986 to December 2005, 88 patients with neck node metastases from an unknown primary cancer were treated with curative intent. The age of the patients ranged from 35 to 74 years (median age, 59 years). There were 74 male and 14 female patients. Distribution of patients by N status was as follows: N1, 4 patients; N2a, 10 patients; N2b, 48 patients; N2c, 8 patients; N3, 18 patients. Fifty-one patients underwent neck dissection and 37 patients had only a biopsy (31 patients had fine-needle aspiration and 6 patients had an excisional biopsy). All patients received radiotherapy. The follow-up time ranged from 1 to 154 months, with a median time of 32 months. RESULTS: The overall survival (OS) and disease-free survival (DFS) rate at 5 years were 43.9% and 41.7%, respectively. The factors associated with the OS rate were neck dissection, and a subsequent primary tumor. Factors associated with the DFS rate were N stage, neck dissection, and a subsequent primary tumor. Neck failure was noted in 15 patients, distant metastases in 18 patients, and a subsequent primary tumor in 8 patients. CONCLUSION: With comprehensive radiotherapy given to the bilateral neck and the potential mucosal sites, good survival rates can be obtained in patients with neck node metastases from an unknown primary cancer. However, considering the side effects, a randomized trial is required to determine the optimal radiotherapy volume.