The aims of this study were to assess epidemiological features, clinical outcomes, laboratory findings, causative organisms and treatment approach for continuous ambulatory peritoneal dialysis (CAPD) -related peritonitis cases. A total of 50 patients (35 male, 15 female; age range: 18-83 years, mean age: 49 +/- 17 years) with CAPD related peritonitis treated in Infectious Diseases and Clinical Microbiology Department of Ankara Training and Research Hospital between February-July 2006 were enrolled into this study. Demographic characteristics, symptoms, physical examination findings and laboratory parameters of patients were recorded and evaluated at the baseline, 48 hours and at the end of treatment. Fifty six peritonitis episodes occurred during the study period., and overall incidence of peritonitis was calculated as 1.6 episodes/patient-year. The most common presenting symptoms were cloudiness of the peritoneal dialysis fluid (100%), abdominal pain (98%), nausea (74%) and vomiting (54%). Abdominal tenderness and rebaund (100%) were the most common physical examination findings. Increased levels of C-reactive protein, erythrocyte sedimentation rate and procalcitonin were detected in 88%, 94% and 42% of the patients, respectively. The mean white blood cell count of peritoneal dialysate fluids was 905/mm(3) (170-17900/mm(3)) in 56 episodes. In direct microscopic examination of peritoneal fluid samples with Gram stain, positivity was detected in 10 (18%) of the attacks, in which eight yielded gram-positive cocci and two gram-negative bacilli. The rate of culture positivity was 74% in the peritonitis episodes, and no microorganism was isolated from the cultures of 26% of the episodes. The most frequently isolated microorganisms were coagulase-positive staphylococci, followed by Staphylococcus aureus (n:4) and Ecoli (n:4) with the rates of 7% of each, Enterococcus spp. (n:3), Klebsiella spp. (n:3) and Pseudomonas spp. (n:3) with the rates of 5% of each, and Streptococcus spp. (n:1), diphtheroid bacillus (n:1) and Candida albicans (n:1) with the rates of 2% of each. Eightyfour percent of patients were successfully treated with intraperitoneal cefazolin and gentamicin empirically. Three of the patient's CAPD therapy was converted to hemodialysis, while two patients have died. As a result, since peritonitis is still the major complication of CAPD despite the technological developments, the informations about causative microorganisms and their antimicrobial susceptibilities would be helpful for, the early and accurate treatment of peritonitis.