Younger adults with epilepsy have an increased mortality. Some deaths are seizure-related, e.g. sudden unexpected death in epilepsy (SUDEP), while others, e.g. suicide, have multiple causes including adverse effects of the treatment on mood. In this retrospective population-based study of all Danish persons with epilepsy aged 18-49 years during 2007-2009 we evaluated the risk of death from seizures and suicide. SUDEP comprised 82.7% of all seizure-related death. Younger adults with epilepsy had an 8.3-fold increased risk of death from seizure-related causes compared with suicide. This underpins the importance of effective seizure control in preventing premature death.