In the present paper, for the first time the multielemental compositionof hair samples of Indian populations living in the Xingu Park Reservation,in the Brazilian Amazonic region has been determined, by INAA. Irradiationswere carried out at the Interfaculty Reactor Institute (Delft, The Netherlands)and, using a combination of different irradiation and decay times, about 40elements could be determined in the hair. Previous analysis made at the RadiochemistryDivision of IPEN/CNEN-SP (Brazilian Nuclear Energy Commission) of hair samplesof a Brazilian control population allowed the determination of 20 elements,also by INAA. Comparison of the data obtained for the Indian populations andthe controls showed very significant differences in elemental compositionsfor some elements, like Hg, Mn and Al while for others, like Cu and Zn, theconcentrations were similar. A discussion of the differences found for otherelements also is made in the present paper.