Peritonitis is a common clinical problem that occurs in patients with end-stage renal disease treated by peritoneal dialysis. The aim of this study was to evaluate the value of blood culture systems for the diagnosis of continuous ambulatory peritoneal dialysis (CAPD) peritonitis among 26 samples of peritoneal fluid obtained from patients with the suspicion of CAPD peritonitis. Significant growth was detected in 12 (70.5%) of 17 bacteria-positive samples. The most striking finding was that 8 (66.6%) of these 12 results were obtained only from blood culture bottles. The identified pathogens were methicillin-sensitive coagulase-negative staphylococci (n = 5), alpha-hemolytic streptococci (n = 2), Corynebacterium spp. (n = 2), Escherichia coli (n = 2), and Enterococcus faecalis (n = 1). Using blood culture bottles inoculated with peritoneal fluid at the bedside, rather than submitting the specimen to the laboratory for later processing, is advocated in the prompt diagnosis of CAPD peritonitis.