Peritonitis is an important cause of morbidity in patients undergoing peritoneal dialysis. Rothia mucilaginosa has been reported as an unusual cause of peritoneal dialysis associated peritonitis. Difficulty in the management of this microorganism lies in the absence of uniform recommendations for anti-microbial therapy directed against this pathogen. The current report describes the clinical course of an episode of peritoneal dialysis associated peritonitis caused by Rothia mucilaginosa. Treatment options for this organism are summarized.