Bone samples from thirty-two uranium miners and eight non-miners were analyzed for 210Pb content. An estimate of cumulative radiation exposure to radon decay products in uranium mines was made for each man and correlated with his bone 210Pb, both before and after adjustments for excretion were made. There is a definite correlation between exposure and bone 210Pb as measured, but the correlation is somewhat better when adjustment for lead excretion is made. The concentration of 210Pb in the bone of uranium miners is related to cumulative exposure (expressed as Working Level Months) by a power function: pCi/g = 4.27 × 10-5 (WLM)l.439. By using a number of reasonable assumptions, it was possible to calculate back from the bone 210Pb to determine the amount of radon daughters inhaled and retained, and from this to calculate radiation dosage delivered to bronchial tissue. These calculations indicate that one Working Level Month delivers approximately 2 rad to bronchial tissue.