The accomplishments of John Snow (1813–1858), physician-epidemiologist, inventor and anaesthetist to Queen Victoria, are well documented, but the causes of his untimely death at age 45 remain conjectural. Snow suffered a paralysing stroke while working on his magnum opus, On Chloroform and Other Anaesthetics, and died a few days later on 16 June 1858. Snow had a history of renal problems associated with tuberculosis. He also experimented on himself with ether, chloroform and other agents over several years, but whether this prolonged self-experimentation contributed to his early death is uncertain. A photograph of Snow taken in 1857 shows that the fingers of his right hand were swollen. Could this be a clue to the cause of his death? The “modern” view is that Snow’s early tuberculosis and associated renal disease led to hypertension, chronic renal failure and stroke. The tuberculosis and renal involvement may have been worsened by vegetarianism and perhaps resulting vitamin D deficiency. However, the renal damage caused by tuberculosis is unlikely to have been progressive. Based on current evidence of renal toxicity associated with exposure to anaesthetic agents, it is perhaps more likely that extensive and prolonged self-experimentation with anaesthetics over a 9-year period led to Snow’s renal failure, swollen fingers and early death from stroke.