Arthur Conan Doyle trained as a medical doctor.

Conan Doyle enrolled in the University of Edinburgh's medical program when he was 17 years old, and he finished his studies there in 1881, earning a Bachelor of Medicine and a Master of Surgery. He finished his M.D. thesis on tables dorsalis, a degenerative neurological condition, four years later. Later, he went to Vienna to further his interest in ophthalmology.

In the English city of Portsmouth, where he also penned his first two Sherlock Holmes books, A Study in Scarlet and The Sign of Four, Conan Doyle started a medical practice. Dr. Joseph Bell, one of Holmes' medical school professors, was modeled in part after him because of his reputation for drawing conclusions about his patients through careful observation.

Conan Doyle moved to London in 1891 to practice ophthalmology. He would later quip that his rented offices had two waiting rooms: "I waited in the consulting room, and no one waited in the waiting room." The endeavor was not a great success. Conan Doyle, though, still had plenty of time to dedicate to his growing writing career. Soon after, he decided to abandon medicine in favor of writing, a choice he later referred to as "one of the great moments of exultation" of his life.