Three human glioma cell lines (TE-671 medulloblastoma, U-87 MG glioblastoma, and U-373 MG glioblastoma) were transplanted to the quadrigeminal cistern of the brain in 37 newborn Sprague-Dawley rats and to the subcutaneous space in 30 of their siblings. Two of the three gliomas (the TE-671 medulloblastoma and the U-87 MG glioblastoma) grew both intracranially and subcutaneously. The U-373 MG glioblastoma did not grow in either site. The resulting tumors expressed unique morphological features characteristic of their tissue of origin. The newborn rat represents a model for the heterologous transplantation of human gliomas, providing a biological window for the study of these lesions.