A total of 636 episodes of peritonitis occurred in 440 patients who entered our continuous ambulatory peritoneal dialysis (CAPD) program from September 1977 to February 1988. Sixteen patients (8 male and 8 female, aged 37-77 years) died during an episode of peritonitis (fatality rate 2.5%). They had been on CAPD for 3 to 105 (average 39) months. Six of them were diabetics. The peritonitis rate among these 16 patients were 1 episode per 12 patient months, while the corresponding figure for the whole (440) CAPD population was 14 patient months. Risk factors present in the 16 patients were: cardiovascular disease (12), cerebrovascular accident (2) peripheral artery disease (1) and pulmonary fibrosis (1). Fever and leukocytosis were present on admission in 11 patients, while total serum proteins and albumin were significantly lower (p less than 0.001) than the corresponding values before peritonitis (56 +/- 8 vs. 65 +/- 5). Staph. aureus was isolated in 8 patients (50%), multiple organisms in 6, Pseudomonas and Candida albicans in 1 each. An abdominal abscess was found in 4 (25%) patients. The peritoneal catheter was removed between the 5th and 10th day in 6 and after the 10th day in 7 patients. Peritonitis with sepsis was the cause of death in 13 patients. Contributing factors were cardiovascular accident in 9, uremic coma in 2, extensive GI bleeding in 2, GI perforation in 2, intestinal infarction in 1, and pneumonia in 2 patients. We conclude that the risk of peritonitis-related death in CAPD patients is increased with Staph. aureus or multibacterial peritonitis. Contributing factors are concomitant cardiovascular disease and delayed (greater than 5 days) catheter removal.