Rasmussen's encephalitis is characterized by seizures, progressive neurological deterioration and chronic inflammation of the brain. It typically presents in childhood and requires anatomic or functional hemispherectomy for seizure control. Here, we report an adult woman who presented with new onset, medically refractory seizures that were not progressive. The patient underwent a right anterior temporal lobectomy. The pathologic samples were consistent with Rasmussen's encephalitis. The patient remained seizure free until her last follow-up at 2 years. This is an example of unique adult onset Rasmussen's encephalitis, suggesting that this encephalitis represents a wide spectrum of presentations rather than a specific disease.