With greater numbers of medical missionaries and colonial state physicians in Britain's tropical colonies at the turn of the twentieth century, British foreign missionaries are thought to have disengaged from medical work. This article redresses this misconception by investigating the training of missionaries in the new tropical medicine at Livingstone College, London, and their subsequent experiences throughout Britain's tropical empire. Many became active in preventative programmes, and were encouraged to spread the principles of modern tropical medicine along with the gospel. Nonetheless, missionaries trained at Livingstone College were not practising medicine that could be described as imperial or tropical. The bulk of their work was basic first aid that resembled care in metropolitan Britain. Therefore, what made the medicine they learned and practised both imperial and tropical, were the ideas, hopes and ambitions placed in it for furthering Britain's imperial goals and winning converts to christianity throughout the tropical empire.