The syndrome of chronic encephalitis with epilepsy (Rasmussen's syndrome) typically occurs in children and is characterized by the development of intractable focal seizures, progressive hemiparesis and intellectual deterioration. The etiology is unknown, and the pathological abnormalities vary. We report the case of a 17-year-old boy, presenting with clinical features typical of probable Rasmussen's syndrome. We discuss the etiology and treatment for this pathology.