Relapsing peritonitis is often due to bacterial colonization of the Tenckhoff catheter and may require removal of the catheter in patients on peritoneal dialysis. The efficacy of a Tenckhoff catheter decontamination procedure was examined in 9 pediatric patients aged 1.5-18 years and compared to the outcome of a historical control group. After repeated dialysate cultures had become negative and cell count was normalized (< 100/ul), intraluminal urokinase (5000 IU/ml) and intraluminal high concentrated antibiotics (vancomycin, fosfomycin, cefotaxim) were instilled sequentially for 3 h and 1 h respectively. This procedure was performed once daily for three days. In addition, the connector was exchanged on the last day. This regimen prevented relapsing peritonitis in all study patients, whereas in the control group in 75.8% of events further relapses occurred, necessitating removal of the Tenckhoff catheter in 7/19 (36.8%) episodes. No side effects of intraluminal urokinase were recorded in any of the patients. We conclude that intraluminal urokinase and intraluminal high concentrated antibiotics combined with connector device exchange are highly effective for prevention of further relapses of peritonitis and reduce the need for Tenckhoff catheter exchange.