Eighteen patients with a glioma of the chiasma were managed between 1980 and 1994. A retrospective analysis of this series showed that the most frequent functional ophthalmological signs were visual loss, nystagmus, or strabismus. Funduscopic examination was abnormal in 65%, mostly with optic atrophy. Other exams (visual field and electrophysiology) were inadequate for diagnosis. Our series demonstrated that early diagnosis of involvement of the chiasma could improve functional prognosis as rapid management can improve prognosis.