For the fi rst time, the toponymy of St. Petersburg is being examined as a historico-medical source and given a classifi cation of medical toponyms of St. Petersburg. We underline fi ve categories of names: given in honor of the medical profession as a whole, given in honor of eminent scientists and other important fi gures in medical fi eld or those who had infl uence on the development of medicine, given in honor of physicians outside the context of their professional activities, given in honor of the medical institutions, given in honor of the medico-social, charitable institutions. In total, the study identifi ed and reviewed 291 medical toponyms relating to 176 objects, some of which still exist, and some that have been since lost. Presently, there are still 93 medical toponyms remain in St. Petersburg.