Over a 3 1/2-year period the permanent Tenckhoff catheter was used in 66 patients (32 men and 34 women) maintained on chronic peritoneal dialysis for periods from 2 1/2 to 36 1/2 months; 57 patients had dialysis in hospital for 20 to 24 hours twice a week and the other 9 had dialysis at home for 10 to 12 hours four times a week. While the Tenckhoff catheter was in place 14 patients received a renal transplant; for 13 who required peritoneal dialysis during the post-transplant phase the Tenckhoff catheter was used. In nine patients abdominal surgery did not interfere with the continuation of peritoneal dialysis via the Tenckhoff catheter. From a total of 5067 dialyses 40 positive cultures were reported (0.8%). Peritonitis was clinically evident on only 14 occasions (0.28%). Permanent catheter obstruction developed in 16 patients, in 11 of whom it was related to peritonitis. With the introduction of the permanent Tenckhoff catheter long-term peritoneal dialysis has become a simple, safe and painless procedure, suitable for virtually all patients who require maintenance dialysis.