Of all the Qing emperors, Yongzhng was the most outstanding believer in Daoism. On the one hand, he used Daoism as an imperial tool for the indoctrination of the people. On the other, he hoped to use it to extend his own lifespan—though it is said that this killed him in the end. This article employs textual research to argue that it probably was Daoist remedies that killed the emperor.