Among the 2,052 children with renal disease admitted to a Pediatric Department during a period of 10 years, 270 developed chronic renal failure (CRF). Of these 270 patients, 147 (54%) were under 5 years of age at the onset of the nephropathy. 182 (76%) reached end-stage renal failure during this period of time of whom 124 (68%) were under 15 years. Five main categories of renal disease leading to CRF were found: glomerular nephropathies (71 cases), hereditary nephropathies (61 cases), renal hypoplasia (59 cases), urinary tract malformations (57 cases), vascular nephropathies (11 cases). A marked predominance of congenital nephropathies (66%), grouping hereditary nephropathies, renal hypoplasia and urinary tract malformations has been noted as compared with acquired nephropathies. Marked differences in age at onset, rate of deterioration of renal function and survival time were found according to the type of renal disease.