© © 2018 American Academy of Neurology. Sudden unexpected death in epilepsy (SUDEP) is the leading cause of premature mortality in patients with refractory epilepsy, but the underlying mechanisms and the predictors of patient risk remain an active area of research. 1,2 At present, risk assessment is based on disease severity accrued over the preceding years, but how the risk changes with therapy and disease progression have been poorly understood. 3 To establish the pathophysiology of SUDEP, studies have capitalized on experimental models 4 and rare terminal events recorded in the epilepsy monitoring unit. 5 In these settings, the seizures are either induced or precipitated by weaning off medications and hence the electrophysiologic changes should be validated with spontaneous seizures recorded over longer time scale. Here we report progressive electrophysiologic changes in ambulatory electrocorticography preceding sudden death in a 38-year-old, right-handed woman who had intractable bitemporal epilepsy.