The severity and incidence of subperiosteal and intracortical bone resorption were evaluated from fine-detail hand radiographs at X 8 magnification in relation to age and sex in 239 chronically dialyzed adult renal failure patients. The severity of subperiosteal resorption decreased significantly with advancing age in both sexes and the incidence decreased somewhat more in males than in females; no such trends were apparent for intracortical resorption. Although the mean values for the grades of subperiosteal and intracortical resorption were significantly higher in females than in males, when the effect of age and duration of follow-up were taken into consideration, this sex difference remained significant only for intracortical resorption. It is concluded that when studying certain aspects of renal osteodystrophy, differences due to age, sex, and duration of follow-up should be considered in the final interpretation of data.