Current information on the adaptations to progressive loss of renal function is presented. The assessment of renal function in infants and children using serum creatinine concentration and its derivatives is considered as are various methods for assessment of growth. Children with creatinine clearances less than 50% of normal, who do not have uremic symptoms (and who are not on dialysis), should be ingesting diets providing close to 100% of the RDA for calories with 8% of the calories as protein. Recommendations for nutritional management of children on chronic peritoneal dialysis are also presented.