Although computed tomography and magnetic resonance imaging have contributed to the ability to identify metastatic disease in head and neck cancer, inadequacies in evaluating lymphadenopathy still exist. This study was undertaken to estimate the accuracy of radiological criteria used to detect cervical lymph node metastases. The morphological characteristics of 957 lymph nodes from 36 neck dissections from patients with squamous cell cancer were examined microscopically. A large number of malignant nodes were found to have diameters of less than 10 mm. Extranodal spread also occurred in a substantial percentage of smaller nodes. Because the present radiological criteria for assessing cervical lymph node status are based largely on size, findings indicate major limitations in the capabilities of detecting metastatic disease. New modalities to improve the staging of head and neck cancer are discussed.