Neurocysticercosis (i.e. cerebral localization of the metacestode larvae of Taenia solium) is believed to be a major cause of late onset epilepsy in non-Muslim developing countries. To define its role in childhood epilepsy in Madagascar, analysis of serological markers of cysticercosis was performed in 256 children with unexplained epilepsy and in 113 controls. Sera were considered positive when high titres in ELISA were present together with at least one of the bands 13, 14, 18, 21, 24 or 32 kD on Western blot. Altogether, 17.6% of the patients versus none of the controls were seropositive using these criteria. When analysing the bands of the Western blot, those of 13, 14 and 18 were significantly more frequently detected in sera of epileptic children than in sera of controls. Neurocysticercosis can be considered the main cause of secondary childhood epilepsy in our country, Madagascar being one of the most important foci in the world.