We retrospectively evaluated the efficacy of neck dissection followed by radiotherapy by using the clinical outcome in 15 patients (median age: 60 years) with upper cervical lymph node (level II) metastasis from unknown primary carcinoma undergoing curative treatment from 1999 to 2007. The male-to-female ratio was 4 : 1, and the histopathological diagnosis in 11 patients (73.3%) was squamous cell carcinoma. Clinical N status was distributed as follows: N1, 1; N2a, 4; N2b, 8; and N2c, 2. Of the 15 patients, 13 patients (86.7%) underwent neck dissection and 11 (84.6%), including 2 unresectable cases undergoing concurrent chemoradiotherapy using DOC and CDDP making their condition resectable, underwent neck dissection combined with radiotherapy. Follow-up was from 5 to 72 months (median: 39 months). In 2 of 6 patients, we detected the primary site at the ipsilateral tonsil through tonsillectomy conducted concurrently with neck dissection. Overall 5-year survival determined by the Kaplan-Meier method was 88.9%, and only 1 patient died of metastasis without achieving complete response 29 months after initial treatment. None of the 15 was observed to have local regional recurrence or distant metastasis after initial treatment. These results indicate that neck dissection followed by radiotherapy is recommended for improving the outcome of patients with cervical lymph node metastasis from an unknown primary carcinoma.