During a 12-year period a total of 203 patients were referred to the oncologic center of Odense with lymph node metastases in the neck. Routine examinations on admission failed to detect the primary tumour in 37 patients. During follow-up, the primary was revealed in 18 of these patients, and in a further 8 cases it was found at autopsy. The primary was most often located in the head and neck region with a possibility of curative therapy. Patients with small neck node metastases responded well to treatment with neck dissection and radiotherapy, resulting in a 5-year crude survival rate of 53%.