The frequency of epilepsy in certain conditions is well known, for example, de novo epilepsy after operative treatment of intracranial abscess is around 70% but this would probably occur independent of the surgical technique used. It seems that craniotomy probably increases the liability of de novo epilepsy by 5-10%. The complexity of the procedure also increases the incidence. Studies of post-traumatic epilepsy with modern imaging techniques have shown the relationship between cortical damage, in particular cortical contusions and post-traumatic epilepsy. The literature on cerebral tumors suggests that late postoperative seizures are more likely to be partial seizures and may be more difficult to control. Antiepileptic drugs (AEDs) are known to be metabolized along established pathways that they may share with other AEDs and also with non-anticonvulsant drugs. Other treatments such as further surgery and adjuvant therapy for intracranial tumors may be useful in treating difficult de novo seizures.