To overcome long-term complications of hemispherectomy, We modified its operative method. The modified hemispherectomy was performed for 31 patients between 1985 and 1992. These patients were studied for 7 years after operation. The results showed total control of seizures in 28 children with chronic epilepsy (90%) or near-total control in the others. No deaths or delayed complications were noted but improvement in behavior and hemiplegia. CT and MRI showed marked shift of the remaining hemisphere. On brain-stem auditory evoked potentials, the latency of peak I was not variant (P > 0.05). The method makes the insulation of the subdural cavity from the ventricular system more reliable, and climates the pathological conditions.