Clinical features of seizures occurring in a neurofibromatosis clinic population were examined in a retrospective study. Twenty-two individuals in a population of 359 persons with neurofibromatos 1 (NF1) had had one or more seizures. Age at first seizure ranged from 4 days to > 20 years. Patients were classified into five groups on the basis of medical history, seizure type, and EEG findings. Two patients had seizures in the first 3 months of life: 1 was born prematurely and had perinatal encephalopathy, and the other developed infantile spasms (IS) and had extensive growth of a plexiform neurofibroma. Two males had seizures in association with aqueductal stenosis. Six individuals had one or more generalized seizures with fever, and 3 had primary generalized epilepsy. Nine patients had complex partial seizures (CPS), which varied in clinical manifestations and response to antiepileptic drugs (AEDs). In none of the individuals with seizures in this study was a structural lesion in the brain visible by neuroimaging. Seizures appear to be relatively uncommon in individuals with NF1, and when they occur have a natural history similar to that of seizures in the general population.