From November 1979 to March 1988, 16 patients with cerebral gangliogliomas were investigated and underwent surgery at the Institute Neurologico "C. Besta" of Milan. Their age varied from 11 to 48 years. 15 of these patients presented with a seizure as the first and often the only neurological symptom. This report deals with the epileptologic and neuroradiologic features of these patients before and after surgical treatment.