We know how important it is to diagnose epilepsy correctly, but how to do so is surprisingly little validated. An inadequate history and misinterpretation of the electroencephalogram (EEG) are the major reasons 4 to 26% of children and adults in European studies are misdiagnosed with epilepsy. Error rates are not available for most countries, or for more precise diagnoses of seizure types, epilepsy syndrome, and cause.