Hidden within the basement archives of Yale University's Historical Medical Library lie the original oil painting collection and personal papers of the first American surgeon to practice in China. The Reverend Dr Peter Parker, a graduate of Yale, established the first American hospital in Guangzhou (formerly Canton) in 1835 and successfully introduced Western surgical techniques including amputation, anesthesia, and reconstructive surgery. In addition to this distinguished career of medical missionary service, Parker commissioned the Chinese artist Lam Qua to paint a fascinating series of portraits depicting patients with extreme tumor growths. In this article, Parker's own journals are examined to reveal both his missionary zeal and his frustrations working in China. Selected examples of the Lam Qua paintings are presented along with Parker's corresponding patient descriptions. These detailed patient reports give insight into the extent of surgical pathology as well as the relative brutality of surgical techniques in the early to mid-1800s. The historical significance of the Peter Parker-Lam Qua collaboration within the context of the Western transformation of Chinese art and medicine is also discussed.