From 1978 through August 1986, 32 patients with lymph node metastases of the neck and unknown primary tumor were treated at the Radiotherapeutic Hospital of the University Erlangen-Nürnberg. Most of the cases were large metastases from squamous cell carcinomas or anaplastic carcinomas. The patients were treated by surgery and postsurgical radiotherapy or radiotherapy alone. In nearly all patients the target volume comprised both sides of the neck including the median structures as well as the base of the tongue and the nasopharynx. A dose of at least 50 Gy was aimed at, which was given within five weeks by individual doses of 2 Gy each. The survival at three years is 70% and at five years 52%. Out of twenty patients irradiated with more than 50 Gy following lymph node extirpation or radical excision of the lymph nodes of the neck, sixteen are tumor-free. The five year survival of this group is 80%. The results of radiotherapy alone are unsatisfactory, because only two out of nine patients are alive with follow-up periods of less than one year. Two primary tumors were found after the end of treatment. Both were situated within the ORL areas beyond the ancient irradiation fields, and both were developed by patients who at first had only been treated by local irradiation. Half of the patients with lymph node metastases of the neck and unknown primary tumors can be cured by complete tumor excision and postsurgical irradiation. The target volume of radiotherapy comprises both sides of the lymph drainage area of the neck as well as the mucous membranes of the ORL region including nasopharynx and base of the tongue. The dose is at least 50 Gy which is given after surgery with conventional fractionation.