OBJECTIVE Supracentimetric cervical lymph node metastasis is classically a poor prognostic factor for locoregional recurrence and survival in head and neck cancer. Causality, however, is more controversial for infracentimetric cervical lymph node metastases. The objective of this study was to evaluate the incidence and prognostic value of infracentimetric lymph node metastasis. METHODS Two hundred and forty-three neck dissections from 150 head and neck cancer patients were analyzed. A single pathologist exhaustively inventoried the number and size of all adenopathies in the surgical specimen. RESULTS Cervical lymph node metastases were infracentimetric in 38% of cases, with 72% extracapsular spread (versus 91% for supracentimetric adenopathies; P<0.01). Infracentimetric metastases were more often associated with other cervical lymph node metastases (mean 5.3 versus 3.9; P=0.14). Fifty three percent of specimens showed only supracentimetric metastases (versus 13% infracentimetric metastases; P<0.01). Disease-specific and failure-free survival were lower in case of infracentimetric metastasis, associated with supracentimetric metastasis or not, than in case of macrometastasis only. CONCLUSIONS Infracentimetric cervical lymph node metastasis is a factor of poor prognosis, and may represent a different, more aggressive lymphatic process. We suggest complete neck dissection by the surgeon and meticulous analysis by the pathologist, the results of which guide complementary therapy. Close surveillance of recurrence is also recommended.