Rothia spp. are gram-positive pleomorphic bacteria that are part of the normal oral microflora. They are associated with dental and periodontal disease, although systemic infections have also been reported. We describe the case of a 75-year-old lady with rheumatoid arthritis who presented with prosthetic knee joint infection due to Rothia aeria. We discuss its identification and the evidence regarding association of dental disease with Rothia spp. joint infections based on available literature.