The case presented in this study illustrates the peritoneal changes observed in long-term peritoneal dialysis (PD) patients. This male patient was on peritoneal dialysis (CAPD) for seven months before and 86 months after renal transplantation. Two episodes of peritonitis occurred during that time. The patient developed symptoms (ascites, gastro-intestinal disturbances, deteriorating general condition, inflammatory syndrome) four months after starting hemodialysis, one month after ablation of the PD catheter. Other potential causes (infection, malignancy, hepatitis, etc.) of these symptoms were ruled out following an exhaustive etiological work-up. A final diagnosis of sclerosing peritonitis was made, and the patient was started on corticosteroid therapy. Both morphological and functional alterations of the peritoneal membrane associated with long term PD and the detection of such alterations in everyday practice are reviewed here, along with possible etiological factors and therapeutic measures discussed in the literature. A better understanding of the pathophysiological mecHanisms underlying these alterations would make it possible to develop preventive measures, such as more biocompatible dialysates.