Radical neck dissection was performed on 43 patients with nasopharyngeal carcinoma in whom persistent or recurrent cervical metastasis developed after radiotherapy. The pathologic nature of the tumor in the cervical lymph nodes was studied with step serial sectioning of the entire radical neck dissection specimen at 3-mm intervals. In 70% of patients, more tumor-harboring lymph nodes were detected in the specimen when compared with clinical examination. The extensive behavior of the tumor in the cervical metastases was reflected by the presence of extracapsular spread in 70% of the lymph nodes and the existence of isolated clusters of tumor cells in 35% of the specimens studied. Tumor tissue lying in close proximity to the spinal accessory nerve was demonstrated in 27.5% of the specimens, and 72% of the tumor-bearing lymph nodes were located in the posterior triangle. Radical neck dissection is recommended as the salvage procedure for these patients.