Peritoneal fibrosis is one of the major causes of technical failure in patients on peritoneal dialysis (PD) for long period of time. Although the exact mechanisms of peritoneal damage during PD still remain unclear, generation of reactive oxygen species may be responsible for progressive membrane dysfunction. N-acetylcysteine (NAC)is a powerful antioxidant shown to protect peritoneal fibrosis in peritoneal dialysis animal model. In this study the researchers investigated the hypothesis that NAC protect peritoneal membrane damage.