100 years ago, in 1894, Alexandre Yersin discovered the causative agent of plaque in Hong Kong. Only a few people know that the native Swiss and student of Pasteur and Roux spent nearly 50 years of his life in Vietnam, where he became director of the Pasteur institutes and earned merits by his engagement for the control of communicable diseases in humans and animals. He, furthermore, successfully introduced tropical plants such as rubber, cacao, coffee and quinquina tree. In 1943, at the age of 80, Yersin died as a personality venerated by all classes of the vietnamese population. During a recent visit to Vietnam the author impressively realised that this veneration is still alive inspite of 30 years of terrible wars and 20 years of communist government.