BACKGROUND There is one published case-control study of nail disorders in hemodialysis patients. The nail changes that occur in renal transplant recipients have not been investigated specifically. OBJECTIVE The aim of this study was to determine prevalence rates of nail disorders in hemodialysis patients and renal transplant recipients, and to investigate whether these nail pathologies are related to hemodialysis and renal transplantation. METHODS One hundred and eighty-two hemodialysis patients and 205 renal transplant recipients were screened for the presence of nail disorders. The findings in these groups were compared with findings in 143 healthy individuals. RESULTS One hundred and twenty-seven patients (69.8%) in the hemodialysis group and 116 patients (56.6%) in the renal transplant recipients had at least one type of nail pathology. Absence of lunula, splinter hemorrhage, and half-and-half nails were significantly more common in the hemodialysis patients than in the renal transplant recipients. Leukonychia was significantly more frequent in the renal transplant recipients than in the hemodialysis patients and controls. CONCLUSIONS Hemodialysis patients and renal transplant recipients have higher rates of nail disease than the healthy population. Renal transplantation may reduce the frequencies of splinter hemorrhage and half-and-half nails. Interestingly, leukonychia increases significantly after renal transplantation.