Yersinia pseudotuberculosis is known to cause septicemia, mesenteric lymphadenitis enteritis and erythema nodosum. Most of the infections were found in European countries, but none in Korea ti11 now. For the first time in Korea Y. pseudotuberculosis was isolated form a 51-year-old ma1e with liver cirrhosis. The patient showed chills, abdominal pain and diarrhea followed by a comatose state. The organism was isolated from both blood and peritoneal fluid. The isolation and identification were difficult as the organism grew slowly and many of the characteristics were similar to other enteric bacilli. The isolate was susceptible to all antibiotics tested in vitro, but our chemotherapy with ampicillin and kanamycin did not save the patient's life.