A case of epilepsia partialis continua (EPC) in a eight year old girl is presented. The episode EPC involved the left side of the face and the left arm and leg with progressive neurologic deficit and mental impairment. The focal seizures did not respond to treatment with a wide variety of antiepileptic drugs. The patient was studied with a 99mTc HMPAO-SPECT in addition to EEG, CT and MRI procedures. During the ictal period the SPECT showed an increased cerebral blood flow in the right hemisphere especially in the Rolandic area and the temporal lobe; during the interictal period a decreased flow was seen in the same regions. The EEG showed marked epileptogenic activity consisting of continued spike and slow wave discharges over the right brain hemisphere; the CT scan was normal and the MRI showed an increased signal intensity in the white and gray matter in the right hemisphere, especially in the frontal and temporal lobes. A temporal lobectomy and a frontal corticectomy were done. The pathologic specimens showed changes consistent with viral encephalitis (Rasmussen's syndrome). The patient has not had seizures in the ten months after surgery. She returned to school three months after surgery, and her IQ was normal. This report illustrates the usefulness of the 99mTc HMPAO-SPECT technique for the diagnosis and the management of EPC cases.