Eosinophilic peritonitis is an uncommon clinical entity with diagnostic considerations separate from those of tuberculous peritonitis. We report a patient on continuous ambulatory peritoneal dialysis (CAPD) with eosinophilic peritonitis resulting from tuberculous peritonitis. Acid-fast stain and mycobacterial culture of peritoneal dialysis effluent were both negative result. In the peritoneal dialysis effluent and blood samples, Mycobacterium tuberculosis was detected by polymerase chain reaction analyses. The initiation of antituberculous therapy resulted in resolution of the eosionphilia in the dialysis effluent. After 14 days of antituberculous therapy, the polymerase chain reaction analyses of tuberculosis were negative for both the blood and peritoneal dialysis effluents. Evaluation of tuberculosis infection is necessary if the CAPD-related peritonitis presents with an unusual and unexplained clinical course. Polymerase chain reaction can play an important role in the diagnosis of tuberculous peritonitis in patients undergoing CAPD.