A retrospective analysis was performed on 410 patients with nasopharyngeal carcinoma of squamous or undifferentiated histotype. All patients were classified according to the classification of the American Joint Committee for Cancer Staging and End-Results Reporting (AJC) and to that of the International Union Against Cancer (UICC, Geneva, 1978). The following prognostic factors were investigated by means of a Weibull multiple regression model: sex, age, histology, primary tumor extent, and nodal metastasis extent. With the exception of sex, all factors significantly influenced survival. With regards to nodal extent, only the level of the involved nodes was a significant variable. Both AJC and UICC classifications, when applied to the entire series of patients, appeared to be unsatisfactory. The authors propose an alternative classification based on a prognostic scoring system directly derived from the Weibull model.