A randomised trial, comparing Tenckhoff catheter replacement as a one-stage procedure and i.p. urokinase, was undertaken in the management of recurrent continuous ambulatory peritoneal dialysis (CAPD) peritonitis. In addition to appropriate i.p. antibiotic treatment, 17 patients received i.p. urokinase (5000 i.u.) on the second and fourth days of antibiotic treatment, and 14 patients underwent CAPD catheter replacement. An additional six patients also underwent catheter replacement following the recurrence of peritonitis after urokinase treatment. The subsequent recurrence rate of peritonitis following CAPD catheter replacement (5%) was significantly less than after urokinase (41%) (p less than 0.001). Fourteen patients remained free of peritonitis for at least three months after catheter replacement, and five patients were peritonitis-free following urokinase for this period.