Non-epileptic paroxysmal movement disorders are rare extrapyramidal diseases. The clinical signs are often excluded from differential diagnosis due to their paucity on clinical examination and low prevalence. The paroxysmal, stereotypical nature of non-epileptic paroxysmal movement disorders, as well as the potential response to benzodiazepines, renders these disorders susceptible to misdiagnosis as epileptic seizures. We report a case of paroxysmal non-kinesigenic dyskinesia which was misdiagnosed and treated as epilepsy for decades. The major pathophysiological, diagnostic and therapeutic hallmarks of the disease are summarised. Familiarity and inclusion of the disease in the list of conditions that mimic epilepsy, as well as prolonged video-EEG recordings, may prevent diagnostic delays and unnecessary or belated treatments. [Published with video sequences].