A 'TGS' classification for supratentorial brain glioma is proposed, based on three parameters: tumour extension (T), histopathological grade (G) and extent of surgical resection (S). Two groups of patients were analysed: the first (n = 137) had tumour submitted to stereotactic biopsy; the second (n = 60) had malignant glioma operated on by craniotomy and tumor resection. All three staging parameters significantly influenced survival. Histopathological grade was the most significant factor, and the only independent variable on multivariate analysis, followed by extent of tumour and then extent of surgical resection. The data support the applicability of the proposed parameters for a staging classification of hemispheric brain glioma.