The purpose of this study was to evaluate the potential of serum CYFRA21-1 and carcinoembryonic antigen (CEA) as prognostic markers in patients with undifferentiated nasopharyngeal carcinoma. Sixty-one patients who received definitive radiotherapy/chemoradiotherapy were analysed retrospectively. We investigated the association of the follow-up results with pretreatment level, post-treatment level and change of serum CYFRA21-1 and CEA, respectively. Patients with low pretreatment CYFRA21-1 had a significantly better overall survival. There were no significant associations among the remaining serum markers, and the survival and recurrence rates on multivariate analysis. The present study shows that pretreatment CYFRA21-1 level is a potential factor for predicting long-term survival.