In this report we evaluate the results obtained with CAPD in uremic patients in Piedmont, a Northern Italian region (4.4 million inhabitants) during the last 7 years. Data are gathered from the computerized records of the regional dialysis and transplantation registry, which collects information on 3,567 pts, 2,243 of which entered since Jan. 1981 and 1,808 alive at Dec. 1987. Among these, 193 (11%) were on CAPD, a figure almost constant in the last 7 years. However CAPD diffusion is not uniform among the 20 centers of the region, ranging from 0 to 49.5% of the patients on dialysis. CAPD is particularly employed in the elderly (47.5% of the patients being older than 60 years and 19.5% over 70). This treatment was the first choice in 16% of the patients admitted to dialysis between 1981-87; this figure reaches 33% for the diabetics. High drop out rates still represent a major problem, in a 6 year follow up 66% of the patients being transferred to another dialysis treatment. Peritonitis is the main cause of drop out (22%), while loss of peritoneal membrane efficiency accounts for 7%, patient's choice 14%, catheter complications 14%, inability to cope 8%, clinical problems 20% and other reasons 15%. Drop out rate is not influenced by the presence of high risk condition or age. Survival curves show no significant difference for CAPD in comparison to hemodialysis in all the age groups considered. This epidemiological survey, based on a global 522 pts experience extended over a 7 year period, indicates that CAPD is a competitive mode of treatment in chronic uremia.