A novel helicobacter with the proposed name Helicobacter aurati (type strain MIT 97-5075c) has been isolated from the inflamed stomachs and ceca of adult Syrian hamsters. The new species is fusiform with multiple bipolar sheathed flagella and periplasmic fibers; it contains urease and gamma-glutamyl transpeptidase. By 16S rRNA sequencing and repetitive element PCR-based DNA fingerprinting, it was found that H. aurati represents a distinct taxon and clusters with Helicobacter muridarum, Helicobacter hepaticus, and Helicobacter sp. MIT 94-022. H. aurati was recovered from hamsters housed in various research and vendor facilities. Further studies are necessary to define its association with disease and other microbiota in hamsters, as well as its impact on research projects involving hamsters. H. aurati (GenBank accession number AF297868) can be used in animal experiments to define the factors that are important for gastric helicobacter pathogenesis.