We report on a young woman with a left temporal diffuse low-grade glioma treated initially by a subtotal resection. A focal anaplastic area appeared 5years later and was treated by radiosurgery. A long-time stabilization was therefore obtained and lasted even after pregnancy, which is a known factor of faster tumour progression. This report shows that radiosurgery could be an option in the multimodal treatment of a selected group of patients with focal malignant transformation of diffuse low-grade glioma. It could permit long-term stabilization of the tumour without any other adjuvant treatment and without compromising the quality of life.