To determine whether toxic and trace elements may play -a role as ail etiologic factor in the development of Parkinson's disease (PD), we measured the levels of toxic and trace elements in the hair from 56 PD patients and 50 normal controls with atomic absorption spectrophotometer In the hair of PD, the zinc concentration showed a significantly lower amount (p=O. 0001) and the concentrations of lead, cad mium, and copper showed a significantly larger amount (Pb, Cd, Cu : p=0.0012, 0. 0444, 0.0286) compared with those of the normal controls. There were no significant differences between the two groups in concentrations of mercury, manganese, iron and aluminum. The levels of each of the toxic and trace elements measured had no significant relationship with Hoehn-Yahr stage, age or the duration of disease. Our data was inconsistent with previous results that analysed the levels of toxic and trace elements in substantia nigra of parkinsonian patients. Due to significant differences in the levels of zinc, copper, lead and cadmium between PD and normal control group, there may be a relationship between PD and those toxic and trace elements. Hair analysis can be so easily applied in clinical practice that a large scale study should be attempted to further evaluate the relationship between trace elements and PD.