Patients presenting with head and neck cancer may have no clinical or radiological evidence of cervical lymph node metastasis – the N0 neck. Despite this, histo-pathological data has confirmed the presence of occult metastases in up to 30% of N0 necks (i.e. N+), depending on the site of the primary tumour. Currently there is no way of identifying affected individuals and consequently, 70% may be overtreated. Using proteomic techniques we attempted to identify a primary tumour phenotype, which would allow the discrimination of oropharyngeal squamous cell carcinoma (OSCC) with metastatic potential.