Three groups of CAPD patients with different dialysis fluids showed a different risk of peritonitis according to the brand of the dialysate and the buffer acetate or lactate they used. Aseptic peritonitis was more frequent with patients who received lactate-buffered peritoneal fluids. According to the manufacturer of the dialysate, however, different results in terms of risk and type of peritonitis are obtained also within one type of lactate-buffered solution. The factors responsible for the difference in the risk of peritonitis according to the dialysis fluids used are unknown.