Endocarditis is a rare manifestation of Yersinia enterocolitica infection. The case of a 45-year-old man who presented with high fever and in whom prosthetic valve Yersinia enterocolitica endocarditis was diagnosed is described. The patient was successfully treated with ceftriaxone plus tobramycin, as proved by negative cultures of the prosthesis removed at the end of therapy. Including the patient reported, only 12 cases of Yersinia enterocolitica endocarditis have been published to date, two of which describe prosthetic cardiac valve endocarditis. The clinical characteristics do not distinguish septicemia from involvement limited to the cardiac valves. Diagnosis, however, has been improved by progress in echocardiography. Prognosis is grave but can be ameliorated if appropriate antimicrobial agents are administered, i.e. the combination of a third-generation cephalosporin plus an aminoglycoside. Fluroquinolones may also constitute an attractive therapeutic alternative.