The Shaykh ul-islam Ibn Kemal’s prolific literary output included medicine but, unlike his multi-volume history of the Ottoman dynasty and works on jurisprudence, his writings on plague and opium have not been contextualized by modern scholarship as part of his scholarly trajectory and rise as the most prominent Ottoman scholar in the first half of the sixteenth century. Through the study of his madrasa appointments and medical works on plague and opium, I argue that he was a medical practitioner who incorporated the language of practice and observation into his works, parallel to his use of oral accounts in his historical writing. In addition to referencing the ancient Greek authors, Ibn Kemal refers to contemporary debates and arguments in his medical works. He likewise draws upon his theoretical knowledge and experience in treating opium addicts through novel methods. In his plague treatise, Ibn Kemal describes how he exchanged medical knowledge with local physicians and observed the spread of and treatments for contagious disease during his travels throughout Anatolia and Syria. Ibn Kemal emphasized the use of vinegar and various citrus fruits for the prevention and treatment of contagious diseases. These prescriptions in which fruits and vegetables played an important role in the medical treatments were part of the rise in the production of fruits and vegetables in the cities and their vicinity and their consumption. In a way similar to his role as a propagandist against the Shi’ite Safavids, Ibn Kemal’s medical writing on the plague (ta’un) advocated different kinds of consumption practices. After presenting his plague treatise to Bayezid II, Ibn Kemal was appointed professor at the state-of-the-art medical school in Edirne where he was able to put into in practice the ideas he advocated in his treatise.