A case is presented in which two neuro-ectodermal tumors, an infra- and a supratentorial glioma, developed in a young man with multiple enchondromatosis of Ollier's disease. This is the third such case of multifocal low-grade glioma in Ollier's disease, suggesting a predisposition for non-mesodermal tumors in Ollier's disease. The related condition of multiple enchondromatosis and hemangiomas (Maffucci's syndrome) is well known for its malignant potential, developing both mesodermal and non-mesodermal tumors. Along with other authors, we support the concept of two variants of the same disease with a predisposition to development of tumors from various germ layers.