Micrococcus lutus is common gram-positive aerobic cocci present in soil, water, dust, and the skin of humans and animals. A 72-year-old man was admitted to the hospital with a complaint of abdominal pain and a turbid peritoneal dialysate. He was empirically treated with intraperitoneal (IP) cefazolin and ceftazidime. Seven day after admission, Gaffkya species was identified from the peritoneal effluent. He was treated with same organism one month ago and discharged with the dialysis catheter intact. So, we suspected that organism is true pathogen, and identified M. luteus by culture. We changed the antibiotics to cefoxitin, which were given for the total of 14 days. This is the first report of relapsing peritonitis by M. luteus and successful treatment without catheter removal.