The incidence and prognostic significance of extracapsular spread (ECS) of tumor in cervical lymphatics was investigated. The surgical specimens from 349 patients treated for squamous cell carcinoma by radical neck dissection between 1978 and 1982 have been examined retrospectively. Follow-up data were available relative to recurrence rate, site of recurrence, and disease-free intervals. Fifty-nine percent of the patients with N1 cervical metastases had ECS. Patients were classified according to the histopathologic findings in the radical neck dissection specimens. The three groups identified were patients with normal nodes, patients with no ECS, and patients with ECS. The histopathologic evidence of ECS was associated with a statistically significant reduction in survival when compared with patients without ECS. The disease-free interval between treatment and the development of recurrent disease was shorter for patients with ECS than for patients with no ECS.