We report a case of reactive arthritis (ReA) triggered by Yersinia enterocolitica enteritis. A 24-year-old Japanese man developed polyarthritis in the lower limbs. Two weeks prior to these symptoms, he noted diarrhea, right lower abdominal pain and a fever. Y. enterocolitica was not isolated from a stool culture; however, he was diagnosed with ReA based on the colonoscopic findings of a high anti-Y. enterocolitica antibody titer and HLA-B27 antigen positivity. Following treatment with methotrexate and steroids, his arthritis improved. This is the first reported Japanese case of ReA in the English literature after a gastrointestinal infection caused by Y. enterocolitica.