Sudden unexpected death in epilepsy (SUDEP) affects up to 5000 patients a year in the United States alone. The exact pathophysiologic processes of are unknown. Profound autonomic dysregulation driving cardiac and respiratory dysfunction is likely. Available evidence from monitored deaths suggests that fatal tachyarrhythmias are not primarily responsible although near deaths due to ventricular arrhythmias have been reported. Genetic "neuro-cardiac" channelopathies affecting brain function, central respiratory processes, and cardiac rhythm have been hypothesized. These, as well as serotonergic mechanisms affecting brainstem homeostasis of cardiac and respiratory function are important areas of current and future SUDEP research.