Optic pathway gliomas represent 2 to 5% of brain tumors in children. Frequently asymptomatic, sometimes they demonstrate rapid growth, causing considerable visual dysfunction, neurologic deficits, and endocrine disturbances. Most optic pathway gliomas are diagnosed in patients with neurofibromatosis 1. Little is known about their natural course; therefore, there are no clear and widely accepted guidelines for their treatment. This study compared the clinical manifestations and natural history of sporadic and neurofibromatosis 1-associated optic pathway gliomas with regard to age at diagnosis, gender, and findings on neurologic, ophthalmologic, and neuroradiologic examinations in 83 children with optic pathway gliomas: 51 children with neurofibromatosis 1 and 32 children without any symptoms or signs of neurofibromatosis 1. A prospective study was performed in 21 patients with neurofibromatosis 1. In the rest of the patients with neurofibromatosis 1 and in 32 children with sporadic tumors, the analysis was carried out retrospectively. There was an increased incidence of females in the group of patients with neurofibromatosis 1 with optic pathway gliomas compared with the entire group of patients with neurofibromatosis 1 remaining for follow-up (P = .013). All optic pathway gliomas were found in children below 10 years of age, slightly earlier in the group without neurofibromatosis 1 (median age 4.6 vs 4.8 years). Children with optic pathway gliomas associated with neurofibromatosis 1 had predominantly multifocal lesions (P = .0001), whereas in the group without neurofibromatosis 1, isolated chiasmal involvement was more common (P = .002). Children with sporadic gliomas had significantly more frequently increased intracranial pressure, decreased visual acuity, and abnormalities of fundus of the eye at the time of diagnosis. The radiologic progression, visual deterioration, and endocrinologic complications were documented on follow-up more commonly in children with sporadic tumors. Our findings support the concept that there is an earlier and more severe clinical presentation of optic pathway gliomas in children with sporadic tumors than in those associated with neurofibromatosis 1.