Sclerosing encapsulating peritonitis (SEP) is characterized by the diffuse appearance of marked sclerotic thickening of the peritoneal membrane. We experienced a case with SEP accompanied by regional changes of peritoneum. A 37-year-old woman with end-stage renal failure was started on continuous ambulatory peritoneal dialysis in 1985 and was transferred to hemodialysis in 1997. She was admitted because of ileus in 1998 with SEP and died of septicemia. The diagnosis of SEP was confirmed via the autopsy. The root of the mesentery was retracted and shortened. Since the peritoneal change was marked in the regions with free margin of mesentery and was less apparent in the regions not adhered to mesentery, it is indicated that mechanical stress also contributes to the occurrence of SEP. Since calcification and ossification were only seen in a free margin of small bowel from mesentery, it is suggested that there is a close relationship between calcification and ossification. Since fibrosis invaded into the muscle layer, dysfunction of bowel movement as well as bowel obstruction contributed to the appearance of ileus. It is suggested that mechanical stress by the root of mesentery which is retracted and shortened also contributes to the appearance of SEP.