It is a well acknowledged fact that poisons play a central role in the Sherlock Holmes stories. It is little known, however, what were Arthur Conan Doyle’s key sources and inspirations for introducing exotic poisons from far reaches of the British Empire. In my article, I make a case for why we should seriously consider India to be an important backdrop, in general, to the Holmes stories, and Indian poisons and corresponding toxicology as the primary data that triggered Doyle’s imagination