Chryseobacterium meningosepticum is rarely encountered as a pathogen causing peritonitis in adults. A 54-year-old woman who underwent continuous ambulatory peritoneal dialysis for 8 years developed peritonitis due to C. meningosepticum. Although she received intravenous antibiotics with good in vitro activity against the organism, the fever and signs of peritonitis persisted. The Tenckhoff catheter was finally removed on the 25th day of hospitalization and the fever subsided. Four isolates of C. meningosepticum recovered from 4 ascites samples drawn on the third, 13th, 18th, and 23rd hospitalization days had identical antibiograms and random amplified DNA polymorphism patterns generated by an arbitrarily primed polymerase chain reaction. Early removal of Tenckhoff catheter and appropriate antimicrobial therapy are crucial to the successful treatment of peritonitis due to C. meningosepticum.