Micrococcus strains which are the normal flora members of skin, mucosa and oropharynx, may lead to infections associated with intravenous catheter, chronic ambulatory peritoneal dialysis, venticular shunt and prosthetic valve. In this paper, a case of peritonitis due to Kocuria rosea of Micrococcea family, in a patient undergoing continuous ambulatory peritoneal dialysis (CAPD), was presented. Fiftysix years old female patient was admitted to the hospital by complaints of abdominal pain, nausea and fever. The patient was undergoing CAPD due to chronic renal failure for one and a half year and turbidity was detected in the peritoneal fluid during dialysis. Examination of the peritoneal fluid revealed 1800 cells/mm3, with no evidence of bacteria in Gram and Ziehl-Neelsen stained smears. No bacterial growth was detected in conventional culture media, however, bacteria was isolated from the peritoneal fluid culture on second day by Bactec (Becton Dickinson, USA) automated blood culture system. By means of API identification system (bioMerieux, USA), the causative agent was identified as Kocuria rosea. The patient was successfully treated with intraperitoneal teicoplanin (4 x 40 mg) for 14 days. In conclusion, in patients undergoing CAPD, rare pathogens should be considered in case of peritonitis and peritoneal fluid samples should be inoculated into automated culture systems.