Peritonitis is still one of the most important complications of peritoneal dialysis. Over the last few years, many efforts have been made in developing new device systems. A remarkable improvement has been obtained by modifying the original connection between the catheter and the bag, especially after the introduction of the Y-set. The aim of this study was to verify whether the use of a new device system, called the T-set, could reduce the incidence of peritonitis. This connector adds the advantages of the Y-set to those of the twin bag. In a group of 53 patients enrolled in a three-year period with a follow-up of 797 patient-months, we observed an incidence of peritonitis of one episode every 50 months. Furthermore, in the subgroup of 39 new patients, we observed an incidence of peritonitis of one episode every 89 patient-months. This new device can be a further step in the evolution of connectors that reduce the incidence of peritonitis.