Sixteen patients with clinical stage II melanoma of unknown primary site (regional lymph node metastasis) were followed up between 1978 and 1988. The 5-year survival rate was 47%. These results seem to parallel those for stage II disease with known primary tumor sites, as has been observed in other data from the literature. The hypotheses put forward to explain such lesions are the spontaneous regression of the primary tumor, and the onset of primary malignant melanoma in the lymph nodes.