The hypothesis that accumulation of trace elements in bone is an etiologic influence in Paget's disease was investigated by comparing the trace element content of pagetoid and normal bone. An initial analysis of iliac bone samples obtained at autopsy from 11 cases and 11 age- and sex-matched controls was carried out using emission spectrometry. Of the 12 elements present in detectable amounts, only lead showed large differences in concentration between diseased and normal bone. Mean lead levels were lower in diseased bone, both in comparison with bone from the controls and in comparison with normal bone from the cases. A second analysis, using atomic absorption spectrometry, was carried out on an additional 10 case/control pairs together with the original 11 pairs. This analysis was restricted to lead, barium, and strontium. Again, mean lead levels were lower in diseased bone. This difference was shown in both case/control groups. When results for the two groups were combined, mean levels of barium were also lower in diseased bone. Mean lead levels in normal bone from cases were lower than those in normal bone from their matched controls, suggesting an abnormality of lead distribution within the skeleton which is not confined to diseased bone.