The risk of sudden unexpected death in patients with epilepsy (SUDEP), is 20 to 25 times greater than in the general population. This increased risk is seen specially in refractory epilepsy, with an incidence of 9:1,000 patients-years. Risk factors have been established based on retrospective studies, finding that the frequency of seizures, specially generalized tonic clonic seizures, is the most important one. The physiopathological mechanism of SUDEP is not yet fully understood. Autonomic system abnormalities, as well as cardiac and respiratory changes have been found. The finding of new molecular biomarkers to identify patients with increased risk should be a priority. Treatment is based in the management of risk factors, although clear recommendations are hard to establish given the low level of evidence.