Rasmussen's encephalitis (RE) is a rare but severe immune-mediated brain disorder leading to unilateral hemispheric atrophy, associated progressive neurological dysfunction with intellectual decline, and intractable seizures. It is a well-established cause of pharmacologically intractable epilepsy. The report is on a 17-month-old infant, treated at the Mario Catarino Rivas Hospital Honduras. Family history: grandfather epileptic secondary trauma from 20 years. Personal history: two previous emergency visits (at 16 months and 16 months 8 days) for convulsions for which she was admitted three days and was treated with valproic acid 30 mg/kg per day. The infant is admitted in the emergency, with a history of about three hours after onset of tonic convulsions, focused on left-side with drooling, oculogiros and relaxation of sphincters and fever of 38.5 ° C. Entered as convulsive syndrome in the study, however, as the days passed the number of seizures increased to 60 per day and was gradually presenting alterations in neurodevelopment. MRI reported leukoencephalopathy of undetermined origin and biopsy reported findings consistent with Rasmussen's syndrome. She was treated with immunoglobulin every two weeks for six doses after two months of hospitalization with achieved improvement. Currently, episodes of seizures have decreased significantly and almost not convulsing, she presented alterations in neurodevelopment.