Encapsulating peritoneal sclerosis (EPS) is a life-threatening complication of peritoneal dialysis. Few data are available from the United States about the incidence of EPS over time. To examine that question, we retrospectively examined our PD registry, in existence for 30 years, to identify patients with EPS. All other data were collected prospectively. We asked a radiologist to review all computed tomography (CT) scans taken at the time of EPS diagnosis. Incidence of EPS in our 676 patients was 1.2%, but rose to 15% after 6 years, and 38% after 9 years on PD. Peritonitis rates were not high in patients that developed EPS. Scoring of CT scans confirmed the diagnosis of EPS in all patients. Treatment was variable, but in recent years, steroids and tamoxifen were generally used when EPS was recognized. Mortality related to EPS was 38%. Several years after diagnosis, 3 patients are still alive; none is on total parenteral nutrition. In summary, the risk of EPS is low early in the course of PD, but increases progressively at 6 years and beyond. Imaging by CT is useful for diagnosing EPS. Our preliminary results suggest that steroids and tamoxifen are beneficial. Multicenter studies on this serious problem are needed.