A 5-year-old boy presented with a 7-month history of headache and projectile vomiting. Computerized axial tomography revealed a large, high density lesion involving the entire left frontal lobe. At operation a 330-g, apparently encapsulated, mildly cystic neoplasm was removed from the region of the left frontal operculum. Microscopic examination demonstrated moderately cellular astrocytic tissue interspersed with several large, bizarre, and occasionally binucleate ganglion cells. The pathological entity of ganglioglioma is briefly reviewed.