The incidence of epilepsy in 323 patients with cerebral palsy (CP) was 41.8%. Almost half of the patients with spastic tetraplegia and hemiplegia had epilepsy. The incidence was lower in patients with spastic diplegia. No sex differences were observed. Partial seizures were by far the most common form of epilepsy in spastic hemiplegia, while generalized tonic-clonic episodes predominated in all other forms of CP. A very high incidence of West syndrome was observed in patients with spastic tetraplegia. Most of the patients with spastic tetraplegia had their first seizure in the first year of life. In patients with spastic hemiplegia the onset of epilepsy was often delayed for several years. A high rate of polytherapy was recorded, but two-thirds of the patients remained seizure-free for long periods. In just over one-fifth of the patients successful withdrawal of medication was achieved.