Neck dissection has a therapeutical as well as a prognostic relevance with respect to regional recurrence and distant metastases. Between January 1973 and July 1986 576 neck dissections in 511 patients (396 men, 115 women, among whom 486 with squamous cell carcinoma of the head and neck, and 14 with neck metastases of an unknown primary tumour) were performed at the department of Otolaryngology-Head and Neck Surgery of the Free University Hospital, Amsterdam. Patients with tumour at the margins were excluded. Recurrence-free curves were calculated according to Kaplan-Meier and the log rank test was used to test the differences. All patients underwent a comprehensive neck dissection and were irradiated postoperatively when three or more tumour-positive nodes or extranodal spread were reported by the pathologist. Endpoint for analysis was occurrence of an ipsilateral neck recurrence or of a distant metastasis. Figures were corrected for a simultaneous recurrence at a higher level. A total of 29 neck recurrences (7.2%; n = 523) and 26 distant metastases (10.7%; n = 281) were demonstrated in the 5-year follow-up period. The number of positive nodes was of prognostic significance for both events (p = 0.039 and p = 0.0027). Extranodal spread was shown only to increase the incidence of distant metastases (p = 0.017), whereas its prognostic value with regard to recurrence in the neck was nullified by the strict institution of postoperative radiotherapy. It is recommended to give radiotherapy to patients with two positive nodes and possibly to every patient with a histopathologically positive neck.(ABSTRACT TRUNCATED AT 250 WORDS)