Background/Aims: Despite effective antibiotic therapy, peritonitis still remains a major problem in peritoneal dialysis (PD). The aim of the present study was to investigate changes of CRP, dialysate leukocytes and IL-6, hyaluronan (HA) and sICAM-1 in dialysate during and after peritonitis and their association to the outcome of peritonitis. Methods: Dialysate IL-6, HA and sICAM-1 were measured at the onset and on day 4, at the end of the treatment and 2 months after onset of peritonitis. Furthermore, CRP and dialysate leukocytes were measured on days 1–4. Results: All measured soluble factors were higher on the first and fourth day than at the end of the treatment. sICAM-1 and HA were lower at the end of the treatment in patients who later had a relapse/re-infection. IL-6 remained higher 2 months after clinically cured peritonitis. CRP and dialysate leukocytes were higher on day 4 in patients with poor outcome. Conclusions: Peritonitis causes increased excretion of soluble factors. Low concentrations of sICAM-1 and HA at the end of the treatment were negative prognostic indicators. Higher IL-6 levels after peritonitis could be a sign of ongoing inflammation in the peritoneal membrane. Delayed decrease in CRP and dialysate leukocytes may indicate poor outcome.