We report a 9-year-old girl with tuberous sclerosis presenting intractable adversive seizure. She had been suffering from frequent attacks of consciousness loss since the age of 6 years. Although a considerable amount of antiepileptic drugs had been administered, her epileptic attacks were not controlled, but instead rather increased. She had been suffering from adversive seizure to the right for more than 2 years. CT scan failed to show any abnormal density area. MRI showed a small lesion in the left frontal subcortical area. The electroencephalogram showed relatively mild abnormal waves in the left hemisphere. We undertook surgical removal of the lesion with epileptogenic foci because her epilepsy has not been controlled and the lesion could be a glioma. Abnormal spike waves were detected around the lesion with electrocorticogram. "Gyrectomy" technique was employed and the spike waves totally disappeared. After the surgery, no neurological deterioration was presented. She has suffered no seizure attack since the surgery even though the amount of the antiepileptic drugs has been significantly decreased. Resection of the epileptogenic foci as well as the abnormal lesion using the technique of gyrectomy is useful for the control of the intractable epilepsy, and makes the quality of life of patients much higher.