Over an 11-year period, from January 1980 to December 1990, 23 patients with metastatic carcinoma of the neck were admitted to Addington Hospital with an unknown primary lesion. More than 50% of patients presented with disease in the N3 nodal stage. Sixteen patients had squamous cell carcinoma, 6 undifferentiated carcinoma and 1 adenocarcinoma. The diagnoses were made by means of fine-needle aspiration cytology and histological assessment of the neck nodes. Twenty-one patients were treated with radiotherapy and 2 with surgery. The primary tumour became apparent in only 4 (17%) patients, 7, 8, 9, and 12 months respectively after initial presentation. The sites were the base of tongue in 2, the pyriform fossa in 1 and the scalp in the remaining patient. The overall 3-year and 5-year survival rates were 26% and 17% respectively.