Open head injuries (OHI) may be classified according to the dynamics of trauma into perforating and penetrating: perforating injuries occur when an object enters and exits the skull, while penetrating injuries occur when the object does not exit the cranial vault. Two types of mechanism for brain damages are described in OHIs: primary and secondary. The diagnosis of post-traumatic epilepsy requires at least two seizures after head injury. Post-traumatic seizures are usually partial at onset even if secondary generalization may be rapid enough to simulate generalized seizures from onset. About 25% of seizures are focal, 50% focal with secondary generalization, while 25% are generalized. The number of damaged brain lobes may be a predictive factor to evaluate the volume of brain loss. Antiepileptic drugs (AEDs) should be administered to all patients with OHI, in both early and late post-injury phases, especially if a significant loss of brain tissue has occurred.