Blood-cadmium (Cd-B) level, blood pressure, and several biological parameters in blood were measured in 440 men who were not occupationally exposed to cadmium and who had a detailed smoking history. No significant correlation was found between Cd-B and blood pressure. Among biological parameters, those known to be related to smoking appeared significantly correlated with Cd-B. Analysis of smoking history showed that Cd-B is strongly elevated in current smokers, with a dose-effect relationship between daily consumption of tobacco and Cd-B; moreover, exsmokers had significantly higher Cd-B than nonsmokers. This finding shows that Cd-B partly reflects past exposure to cadmium.