Optic nerve glioma is a rare tumor usually occurring in small children. How these tumors should be treated, is a matter of controversy. Recommended treatment ranges from a wait-and-see policy to radical excision with or without subsequent radio- or chemotherapy. Comparative data on these lesion are limited, as there are no randomized investigations and long-term studies reported in the literature. In 11 patients interstitial radiotherapy was carried out, by the implantation of J-125 seeds following confirmation of the histological diagnosis. The results are compared with those of 10 patients who underwent only biopsy for histological confirmation. CT-stereotactic biopsy to verify the diagnosis with subsequent interstitial irradiation is presented as an alternative therapy for optic gliomas.