To perform continuous ambulatory peritoneal dialysis (CAPD), a safe and easy bag exchange system must be established. The authors developed a new system called "Safedap" and applied it to clinical cases. Safedap consists of a bottom, a sleeve, a shell, and a lock-type connector. The bottom and sleeve are made into one unit with a preembedded sponge saturated with 10% povidone-iodine for disinfection and protection. Safedap was introduced to 23 patients who were observed for a period of 293 patient months. Sixteen patients used a standard spike and functioned as controls. Peritonitis rates were 1/73.3 patient months in Safedap (4 episodes in 3 patients) and 1/30.1 patient months in controls (10 episodes in 7 patients; p less than 0.05). Using life table analysis, the probability of a control being peritonitis free at 12 months was 0.63 versus 0.95 in those using Safedap (p less than 0.05). By allowing completion of bag exchanges safely and rapidly, Safedap is effective in reducing the occurrence rate of peritonitis.