This special issue of Applied Radiation and Isotopes is devoted to the 19th International Conference on Radionuclide Metrology and its Applications (ICRM 2013), which was held from 17 - 21 June 2013 at the Congress Centrum Elzenveld in Antwerp, Belgium. The conference was organised by the European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (EC-JRC-IRMM), the local organisation was undertaken by the Radionuclide Metrology group of JRC-IRMM. The 19th International Conference on Radionuclide Metrology and its Applications (ICRM 2013) was attended by 178 participants from 42 countries worldwide. Of the 166 submitted abstracts, 2 invited talks, 39 oral contributions and 76 posters were presented at the symposium. 104 papers are published in these proceedings, accepted after a very rigorous reviewing process.