Comamonas testosteroni(C. testosteroni) has been rarely observed as an infectious agent in clinical practice. Few reports described its potential pathogenicity in bloodstream and abdominal infections. Here, we report our experience in the treatment of a C. testosteroni-associated peritonitis in a four-year-old girl receiving chronic peritoneal dialysis(PD). The organism was shown to be highly susceptible to appropriate antibiotic therapy. Infection responded promptly and the patient was managed conservatively without withdrawal from PD. Cowmon testosteroni (C. testosteroni) has been observed as an infectious agent in clinical practice. Few reports describing its potential pathogenicity in bloodstream and abdominal infections. Here, we report our experience in the treatment of a C. testosteroni-associated peritonitis in a four-year-old girl receiving chronic peritoneal dialysis (PD). The organism was shown to highly highly susceptible to appropriate antibiotic therapy. Infection managed promptly and the patient was managed conservatively without withdrawal from PD.