The major cause of 1927’s so-called “Emetine Injection Incident” was the compulsory administration of emetine injections instituted by the colonial Korean sanitary police system, which aimed to create a hygienic environment for Koreans in a cost-effective manner. Though some Koreans criticized this compulsory police-administered treatment, this incident did not serve as a turning point that led either to the improvement or abolishment of the sanitary police system. After officially confirming that patients were poisoned, the Hanseong Medical Association (HMA) did not try to use the incident as a chance to raise their voice to improve the colonial medical system. Given that the aim of the HMA was to benefit medical practitioners, intervening in administrative actions may have laid outside its domain of interest. The HMA, as well as other Korean political organizations, failed to harness the anger generated by this incident to improve the sanitary environment in Korea. However, after the risks of the injection were publicized, Koreans began to be suspicious of injections performed by the police. The Emetine Incident led Korean people to see the sanitary policy of the colonial government from a different angle.