Napoleon Bonaparte (1769 to 1821) is one of the most studied historical figures in European history. Not surprisingly, amongst the many mysteries still surrounding his person is the cause of his death, and particularly the suspicion that he was poisoned, continue to intrigue medical historians. After the defeat of the Napoleonic Army at the battle of Waterloo in 1815, Napoleon was exiled to the small island of Saint Helena in the South Atlantic, where he died 6 years later. Although his personal physician, Dr François Carlo Antommarchi, stated in his autopsy report that stomach cancer was the cause of death, this diagnosis was challenged in 1961 by the finding of an elevated arsenic concentration in one of Napoleon's hair samples. At that time it was suggested that Napoleon had been poisoned by one of his companions in exile who was allegedly supported by the British Government. Since then Napoleon's cause of death continues to be a topic of debate. The aim of this review is to use a multidisciplinary approach to provide a systematic and critical assessment of Napoleon's cause of death.