The grey silverfish Ctenolepisma longicaudatum is a new and serious pest spreading rapidly across Europe. Compared to the silverfish Lepisma saccharinum , it does not depend on relative humidity above 70% and thrives also in new museum buildings, modern storage depositories, apartments, and office buildings. Especially collections of graphic art, modern art on paper, photographs, but also archives and libraries are increasingly affected by this pest. Damage of paper objects has been reported by different authors and institutions across Europe. As these animals live in inaccessible cracks and crevices inside the buildings, we investigated the spread of microorganisms on living grey silverfish, to show a potential additional threat posed by this pest. In 8 locations in Austria living animals were collected with traps and placed for 10 min on agar plates which were incubated for 2 weeks. After incubation of 50 agar plates, between 2 and 20 colonies of fungi were growing on each plate. The most dominant fungal genera were Cladosporium ( Cladosporium cladosporioides clade) and Penicillium ( Penicillium glabrum, Penicillium decumbens ); also, species of the genera Aspergillus , Alternaria , Botrytis , Bartalinia , Byssochlamis , Chaetomium and Mycothypha were found. The diversity of fungi reflects the common fungal community of museums and archives. The spores and mycelial fragments of the fungi are obviously travelling on the legs and bodies of the silverfish.