A 62-year-old female patient was given cancer chemotherapy for lymph nodes metastases in the left breast cancer. She was admitted to the hospital because of severe watery diarrhea, in hypovolemic shock, and was diagnosed as suffering from not-typhoidal Salmonella by stool culture. After systemic administration of antibiotic agents, she became well in a few days, but on the 16th hospital day, she had severe watery diarrhea, hypovolemic shock and then cardiac arrest. She was resuscitated immediately. The stool culture revealed methicillin-resistant Staphylococcus aureus (MRSA), type II coagulase, producing TSST-1 and type BC staphylococcal enterotoxin. It was thought that in this case, MRSA enteritis was caused by damage of the intestinal mucosal barrier of the defense mechanism against infection due to salmonellosis and administration of multiple antibiotic agents.