The author argues that medical illustration is not a cross-cultural phenomenon known since ancient times, but a modern tradition born out of the intellectual climate of 18th century Europe. In this climate, photography was always desirable in theory, and medical illustrators grasped photographic technology as soon as it became available in the 1840s, quickly adapting it to their own purposes. The earliest surviving clinical photograph can be identified as that of a woman with a goitre taken by Hill and Adamson ca. 1847, in which case medical photography has this year reached its 150th anniversary. The author also offers a revised account of the speed and enthusiasm with which early medical illustrators recognized the opportunities afforded by new forms of technology.