Originated by Samuel Hahnemann (1755–1843), homeopathy is a method of selecting and preparing medications by matching effects. Homeopathy is built on two key principles: the Law of Similars and the Law of Infinitesimals. The Hong Kong Association of Homeopathy was founded in 2007 with a view to promoting the study and practice of homeopathic medicine.1 But the therapy—known in Chinese as shunshi liaofa and tongyang liaofa—had been introduced to the colony half a century earlier, at a time when many called for modernizing Chinese medicine. Few doctors trained in Western medicine took it up because the focus was on how to integrate this new technique from the West into traditional medicine. This paper traces the history of homeopathy in Hong Kong and discusses its relationship to efforts to render Chinese medicine more scientific.