Dr. Reinhard Hoeppli (1893—1973), a well-known Swiss medical parasitologist, completed his clinical training in Germany, obtained a doctorate in clinical pathology related to parasites, and later conducted nematology research in the United States. From 1930 to 1952, he served as the second Director of the Division of Parasitology at Peking Union Medical College (PUMC), and was responsible for the examination of parasite-related specimens in the PUMC Hospital. During his time at PUMC, Dr. Hoeppli discovered the famous "Splendore-Hoeppli Phenomenon", and contributed greatly to the advancement of medical parasitology and tropical diseases in China. In addition to his academic achievements, he made fruitful diplomatic efforts for PUMC in his capacity as Swiss consul during the occupation of PUMC by Japanese forces. This paper mainly reviews his great influence on the development of medical parasitology during the time at PUMC and his diplomatic contributions to PUMC.