The aim of the 5th International Conference on Radioecology and Environmental Radioactivity was to review and discuss recent achievements in radioecology, environmental radioactivity and related disciplines, as well as to promote continued development in these subjects in order to improve the radiological protection of humans and the environment (https://www.icrer.org/). ALLIANCE marked 10th anniversary in the special session ‘Radioecology ALLIANCE 10 years’ while additionally ALLIANCE poster prizes were given to three young colleagues for the best posters presented at the conference.