Abstract A novel coccoid, anaerobic, Fe2+-oxidizing archaeum was isolated from a shallow submarine hydrothermal system at Vulcano, Italy. In addition to ferrous iron, H2 and sulfide served as electron donors. NO3 was used as electron acceptor. In the presence of H2, also S2O32 could serve as electron acceptor. The isolate was a neutrophilic hyperthermophile that grew between 65C and 95C. It represents a novel genus among the Archaeoglobales that we name Ferroglobus. The type species is Ferroglobus placidus (DSM 10642).