Background: A late (>5 years) neck nodal metastasis of oral cancer, poses a problem to the clinician: is it a late metastasis or a metastasis of a (unknown) second primary tumour? Methods: A 50-year-old male was seen with a contralateral lymph node metastasis, 51/2 years after treatment of a pT2N1M0 carcinoma in the floor of the mouth. Both the late metastasis and the original tumour specimen were analysed for p53 mutations. Results: Both specimens showed an identical p53 mutation, thereby confirming the lymph node to be a late metastasis. Conclusions: A lymph node metastasis can occur more than 5 years after treatment of an oral squamous cell carcinoma. p53 mutation analysis is of help to discriminate it from a second primary tumour. (C) 2008 European Association for Cranio-Maxillofacial Surgery.