A concern of safety issue for traditional herbal medicine is the possibility of some herbscontaining heavy metals responsible for several cases of metal poisoning. In our previous study,the physiological levels of heavy metals, such as Cd, Cu, Hg and Pb, were examined to evaluate apotential risk in patients taking herbal medicine. In this study, the levels of 12 heavy metals,including non-metallic element, Se, were analyzed in hair and compared to the results from theprevious study. In the previous study, the levels of Cd, Cu, Hg and Pb in hair showed a significantlylower odds ratio than 1. In this study, however, all metals did not show any significant odds ratiohigher or lower than 1 even if 5 of 12 metals showed lower odds ratio than 1. In addition, the levelsof metal concentrations, especially for Cu, Fe, Pb and Zn, exceeding the WHO reference values wereobserved in hair. However, any evidence for metal accumulation in hair caused by taking herbalmedicines for long duration was not observed in analysis of multiple regression and odds ratio fromcase-control study. This result would show another possibility for a role of herbs as a non-enzymaticchelator inhibiting the gastrointestinal absorption of heavy metals.