[en] ''Metrology of Radionuclides'' is the science of precise measurements of the absolute value of the activity of radioactive sources. A rapid expansion has taken place over the past few years in the applications of radionuclides in various fields of scientific research, particularly in the production of commodities which lead to improved living standards. This has occurred not only in the countries most advanced in nuclear science, but in many others. In order to allow those actively engaged in this field to exchange research results and discuss their problems, the International Atomic Energy Agency sponsored a symposium which was held in Vienna from 14-16 October, 1959. Thirty-seven papers were presented from 14 countries. These covered a general survey on the routine methods of standardization of radionuclides and new developments of absolute measuring methods for their standardization.