The onset of a protein-energy malnutrition represents a real risk for patients on CAPD. In order to verify the nutritional status and the effectiveness of the dietetic surveillance in preventing this complication, dietary intake, anthropometric measurements and biochemical parameters were monitored in 46 patients (27 males, 19 females, mean age: 58.7 +/- 14.8 years), suffering from ESRF and treated with CAPD, for a total observation period of 1731.67 months (mean: 37.64 +/- 25.17 months). The mean glucose concentration in the dialysate was 2.00 +/- 0.36 g/dl, the glucose reabsorption from dialysate per kg of ideal body weight (kg-IBW) was equivalent to 5.1 kcal, the mean dialysate protein loss was 13.08 +/- 5.52 g/day and the incidence of peritonitis episodes was 1 every 30.38 months-patient. The daily total caloric intake (by mouth and dialysate) was 30.8 kcal/kg-IBW with a normal subdivision for each diet component: there were not statistically significant differences in distribution according to age, sex and in the follow-up. The mean daily value of protein intake (PI) evaluated by dietary interviews was 0.99 g/kg-IBW, with a significant increase 1 year since the beginning of CAPD; the PI evaluated from urea nitrogen appearance was 1.22 g/kg-IBW. The PI remained stable later in the follow-up and in patients that made use of dietetic supplements, the mean daily increase by this way was 0.47 g/kg-IBW. Anthropometric measurements showed a statistically significant increase of %RBW after 1 year and of TS and % body fat after 3 years.(ABSTRACT TRUNCATED AT 250 WORDS)