ONE of the most significant developments in the treatment of end-stage renal disease during the last 10 yr has been the emergence of continuous ambulatory peritoneal dialysis (CAPD) as a treatment modality. Intermittent peritoneal dialysis (IPD) has been available for many years but because of problems with infection and with the equipment has never been used widely. Currently, IPD is used by only 1610 patients (2.7%) of all dialysis patients in the United States. Since its introduction by Popovich and Moncrief in 1976,1 after a slow start, CAPD has shown a meteoric increase in the number of patients treated both in the United States and Europe. As of December 31, 1981, there were 4330 patients on CAPD in the United States (45.8% of all home dialysis and 7.4% of all dialysis patients), 2 and by March, 1982, the number was unofficially reported as having risen to 5397 patients. 3 There were an additional 6000 patients elsewhere in the world on CAPD, and CAPD was reported as being the treatment for 3035% of patients in New Zealand, 24% of patients in Australia and Canada, and 20% in the United Kingdom, while at the other extreme it is only used by 1 % or less of patients in Israel, Germany, and Japan. 3 Why was there this rapid increase in use of an unfamiliar and new therapy? Was this solely the result of publicity and pressure by the manufacturer? How much does the use of CAPD result from pressure by patients who wish to do home dialysis? Is CAPD as simple and safe as has been claimed? Has CAPD been endorsed too enthusiastically and too quickly? Is CAPD really as costsaving a modality of treatment as has been claimed? These and other questions have not been adequately answered. The accompanying articles. one from Toronto where enthusiasm for CAPD is extremely high. and one from Minneapolis from a very experienced dialysis and transplant center where results with CAPD have been disappoint-