A visual summary of underlying patterns in metastases from oral squamous cell carcinoma (SCC) was created by the mathematical technique of multidimensional scaling (MDS). MDS creates a "functional" map of the neck, such that adjacent sites share similar probabilities of disease. We mapped the metastases from 130 sequential cases of oral SCC in the UK. Binary Euclidean distances were calculated from tallies of metastases at all possible pairs of neck levels (I-V on each side) for each of seven different primary sites: buccal mucosa, lower alveolus, floor of mouth, ventral tongue/floor of mouth, lateral tongue, retromolar trigone, and oropharynx. A two-dimensional functional map of the neck was made from these distances. The map explains 82% of the input data (p < 0.01). This is the first functional mapping of neck levels. The technique can now be used to summarize and compare patterns of metastases in different populations.