Gamma knife radiosurgery is a minimally invasive procedure which can be used for patients with intractable epilepsies as an alternative for surgical corpus callosotomy. We report a 13-year-old boy with intractable epilepsy who underwent radiosurgical callosotomy. The patient demonstrated significant clinical improvement after gamma knife radiosurgery and was free of seizures 10 months after the procedure. However, He developed four short focal seizures with clonic movements during the 20 months post radiosurgery. Corpus callosotomy decreased epileptiform discharges in both hemispheres, indicating a role for the callosal neurons to facilitate an asymmetric epileptogenic susceptible state within the two hemispheres such that bisynchronous and bisymmetrical epileptiform discharges develop. Our result demonstrates that this novel therapeutic approach is a safe and effective option for the treatment of intractable generalised epilepsies.