The activity concentrations of 137Cs and 40K in mushrooms of the genus Cantharellus (Cantharellus cibarius, Cantharellus tubaeformis, and Cantharellus minor) collected across Poland from 1997 to 2013 and in Yunnan province of China in 2013 were determined using gamma spectrometry with an HPGe detector, respectively. Activity concentrations of 137Cs in C. cibarius from the places in Poland varied from 64 ± 3 to 1600 ± 47 Bq kg−1 db in 1997–2004 and 4.2 ± 1.2 to 1400 ± 15 Bq kg−1 db in 2006–2013. In the Chinese Cantharellus mushrooms, the activity level of 137Cs was very low, i.e., at a range <1.2 to 1.2 ± 0.6 Bq kg−1 dry biomass. The natural radionuclide 40K was at similar activity level in C. cibarius collected across Poland and in China, and fluctuations in levels of 40K over the years and locations in Poland were small. In C. cibarius from diverse sites in Poland, content of 137Cs highly fluctuated in 1998–2013 but no clear downward trend was visible (Fig. 1). Published activity levels of 137Cs in fruitbodies of Cantharellus such Cantharellus californicus, Cantharellus cascadensis, C. cibarius, Cantharellus cinnabarius, Cantharellus formosus, Cantharellus iuteocomus, Cantharellus lutescens, Cantharellus minor, Cantharellus pallens [current name C. cibarius], Cantharellus subalbidus, Cantharellus subpruinosus, and C. tubaeformis collected worldwide were compared. In the Polish cuisine, mushrooms of the genus Cantharellus are blanched before frying or pickling, and this kind of treatment, and additionally also pickling, both very efficiently remove alkali elements (and radioactivity from 134/137Cs) from flesh of the species.