Dried sclerotia of Wolfiporia extensa has a long history of medicinal and grocery uses in Asia and elsewhere. This study aimed at providing and evaluating data on activity concentrations from artificial 137Cs and 134Cs radionuclides and natural 40K in sclerotia collected across of the Yunnan land in China, which is generally lacking information. Sclerotia of W. extensa showed a low contamination with 137Cs while 134Cs was below limit of quantification. Estimated, the nominal value of effective dose (μSv) received by adult eating annually 50 g of the ‘average’ Yunnan's origin sclerotia contained in the ‘Fuling jiabing’ snack due to 137Cs could be between < 0.00091 and 0.0047 ± 0.0007 μSv per capita and at < 0.000015 to 0.000078 ± 0.000012 μSv per kg of body mass, which is a very low exposure. This study has revealed also that sclerotia of W. extensa are characterized by very low content of 40K (hence also of total K) when compared to fruiting bodies of many saprobic and mycorrhizal mushrooms.