Thirty-eight children (aged 2-16 years) attending a regional kidney unit had a full clinical and radiological dental examination. Twenty had previously undergone a renal transplant, 11 had chronic renal failure and 7 had other renal diseases. Periodontal disease was uncommon The presence of gingival hyperplasia (gum overgrowth), as recorded in 22 of the children, did not show any relationship with the use of immunosuppressant therapy. However, gingival overgrowth was so excessive in 2 patients that surgical removal was required. The prevalence of dental caries was low. Enamel defects were common, and of an unusual pattern, with a much higher prevalence of diffuse opacities and enamel hypoplasia than in the normal child population, 83% and 22%, respectively. This increased prevalence is probably due to disordered calcium and phosphate metabolism. The prevalence of these defects may reflect an early onset of renal disease, since there were a number of very young children in the programme. Dental and medical care should be closely integrated for children with renal disease to avoid the undesirable dental sequelae of, in particular, gingival overgrowth, carcinoma and enamel hypoplasia.