The identity of symbiotic fungi associated with the Xiphydria spp. wood wasps was investigated using DNA analysis. The fungi were isolated from the mycangia of adult females of X. camelus, X. prolongata and X. longicollis reared from colonized logs of Alnus glutinosa, Salix alba and Quercus robur, respectively. Sequences of rDNA and beta-tubulin were obtained. Phylogenetic analysis based on the NJ method showed that the isolates from X. camelus clustered with Daldinia decipiens, whereas those of X. prolongata belonged to Entonaema cinnabarina. In X. longicollis, both symbiotic fungi (D. decipiens and E. cinnabarina) have been found. Morphological characteristics of the anamorphs are presented. In cultures of D. decipiens, sympodial holoblastic, as well as annelidic, conidiation was observed. So far, fruit bodies of D. decipiens have only been recorded from Betula spp. whereas the host spectrum of its wasp vectors covers predominantly oaks and alders. Fruiting bodies of E. cinnabarina do not occur in Central Europe. This is the first report of Entonaema as a symbiotic fungus of siricid wood wasps.