Sclerosing encapsulating peritonitis (SEP) is a rare but serious complication in patients with continuous ambulatory peritoneal dialysis (CAPD), and is characterized by a progressive, intra-abdominal, inflammatory process resulting in the formation of sheets of new fibrous tissue, which cover, bind, and constrict the viscera, thereby compromising the motility of the bowel. No satisfactory estimate is available on the comparative incidence of dialysis related SEP and the pathogenesis of SEP still remains uncertain. Although recent therapeutic approaches have reported varying degrees of success, an efficient measure to detect, at an early stage, patients at risk for SEP would be beneficial and a standardized treatment regimen to prevent the illness is urgently needed. This study aimed to evaluate the clinical features of SEP and to identify the possible risk factors for the development of SEP in CAPD patients. We retrospectively reviewed by questionnaire SEP cases among CAPD patients from 7 university hospital dialysis centers in Korea, including Yonsei University, Ajou University, Catholic University, Inha University, Kyungpook University, Seoul National University and Soonchunhyang University, from January 1981 to December 2002. Out of a total of 4,290 CAPD patients in these centers, 34 cases developed SEP with an overall prevalence of 0.79%. The male to female ratio was 17:17. The median age of these patients was 44.5 years (range 19-66). The median duration of CAPD before SEP was 64 months (9-144) and 68% of patients (23/34) had been on CAPD for more than 4 years. Peritonitis (including two fungal cases) was the main cause of catheter removal in SEP (27 cases, 79%). Seventy-five percent of the cases (15/20) were administered beta-blocker for a mean duration of 85 months (26-130). Among 10 cases with available peritoneal equilibration test (PET) data, 8 showed high transporter characteristics, and the remaining 2 were high average. Eighteen cases were diagnosed by clinical and radiologic methods, and 16 were surgically diagnosed. Eleven cases were surgically treated and the others were treated conservatively with intermittent total parenteral nutrition (TPN). The overall mortality rate was 24%. SEP is a serious, life threatening complication of CAPD. Most cases had a PD duration of more than 4 years, a history of severe peritonitis, and high transporter characteristics in PET. Therefore, to reduce the incidence of SEP, careful monitoring and treatment, including early catheter removal in patients with severe peritonitis, should be considered for long-term CAPD patients with the above characteristics.