OBJECTIVE To observe the Chinese herbal medicine Selaginella-induced radiosensitization of terminal nasopharyngeal carcinoma (NPC). METHODS Totally 180 patients with NPC were divided equally into 3 groups with the same radiotherapeutic protocols. The patients in group A received radiotherapy alone, those in group B were given daily Selaginella (30 g) prepared into 50 ml decoction during the entire course of radiotherapy, and those in group C had Selaginella 30 g daily in the late course of radiotherapy. RESULTS The complete remission rate of nasopharyngeal primary lesions in groups B and C was significantly higher than that in group A, with also significantly higher complete remission rates of the cervical lymph nodes. The acute toxicity of the skin and mucous membrane was milder in the latter two groups, but the differences were not significant. CONCLUSIONS Selaginella may induce radiosensitization for terminal NPC and does not increase the acute toxicity of radiotherapy.